Follow TV Tropes


Useful Notes / Stock Dinosaurs (True Dinosaurs)

Go To

This page is about dinosaurs. Dinosaurs were a varied group of archosaurian reptiles, including bipedal, quadrupedal, carnivorous, herbivorous and omnivorous species, ranging from the size of small birds to large whales.

All non-bird dinosaurs so far known, as well as the first birds, lived in the Mesozoic Era, nicknamed "The Age of Dinosaurs", 252-66 million years ago (mya). The era is divided by geologists and paleontologists into three periods; from the most ancient to the most recent, they are the Triassic, Jurassic, and Cretaceous. You'll notice that most stock dinosaurs come from North America during either the Late Jurassic or the Late Cretaceous.


Note that

  • No one dinosaur species lived through the entire era, nor were they evenly distributed over the world.
  • Hence, the dinosaurs didn't all live together in the same time and place.
  • No humans lived contemporaneously with Mesozoic dinosaurs.

Many depictions of dinosaurs break one or more of these rules (and other, more specific rules as well). When this happens, we get Anachronism Stew and Misplaced Wildlife, and it's easy to say that Artistic License – Paleontology is in play. It is possible for works to follow the rules and still misrepresent dinosaurs, because Science Marches On and "hard fact" is nowhere near the same today as it was a century ago (or in some cases a decade ago).

Dinosaurs and other extinct animals are divided here into four categories:

  1. Great Stock: *** What you think of when you think "Dinosaur"; have appeared everywhere in the media.
  2. Middle Stock: ** Have frequently appeared in media but less-frequently than the Great Stock. Some are closely-related to the latter and may be used as their substitutes in fictional works.
  3. Little Stock: * Have frequently appeared in documentary media but quite rarely in the more popular ones. Their presence in fiction might actually be seen as an aversion of the trope.
  4. Non-Stock: Have appeared even more seldom in media (if at all). note  See Useful Notes Prehistoric Life for these.

Stock dinosaurs are usually among the biggest/most impressive members of each dinosaur subgroup, but not necessarily the most common in the fossil record. Just as an example, Tyrannosaurus rex is known only from a dozen specimens, while other less popular dinosaurs have left hundreds of skeletons or even more. At the other extreme, several dinosaurs have left to us one single bone or tooth.

A brief history of popular depictions of dinosaurs

See here for a more detailed article.

1850s: The Crystal Palace dinosaur sculptures in London introduced dinosaurs to the public. The image they provided was of scaly, bulky, four-legged dragons (quite un-dinosaurian critters to our modern view). Introducing: Iguanodon, Megalosaurus, and Hylaeosaurus. The park also introduced some non-dinosaur reptiles: the flying Pterodactylus and the swimming Mosasaurus, Ichthyosaurus, and Plesiosaurus. The 1864 novel Journey to the Center of the Earth portrayed the latter two as the first "antediluvian reptiles" ever in literature. The first mention of a proper dinosaur in fiction, believe it or not, was by Charles Dickens, who in the opening paragraph of Bleak House (1853) described the streets of London as being so muddy he could imagine a Megalosaurus lumbering up them!


Late 1800s: The excitement of the U.S. Bone Wars made dinosaurs interesting to the readership of newspapers and magazines that recounted the exploits and discoveries of Marsh and Cope. Stock dinosaurs found: Brontosaurus (Apatosaurus, though at the moment said synonymy is kind of rocky), Camarasaurus, Diplodocus, Allosaurus, Ceratosaurus, Stegosaurus, Triceratops, Trachodon (Edmontosaurus), Camptosaurus, Dryosaurus, Hesperornis, and Ichthyornis. Non-dinosaurs found: Pteranodon, Elasmosaurus, Tylosaurus, and Dimetrodon.

Early 1900s: Updated depictions of dinosaurs were brought to the general public by early paleoartists (beginning with Charles R. Knight), by distribution of skeleton casts which made life-sized and fairly life-like museum exhibits possible, and by dinosaurs being introduced to films. From this time on, dinosaurs and movie special effects were tightly coupled. Based on the finds during and since the Bone Wars, dinosaurs were now seen as a more varied bunch, with larger and... less large forms, bipedal or quadrupedal. They were still sluggish brutes destined for complete extinction, though. In 1940 Disney's Fantasia reached a large audience, but didn't change the media image much. Introducing: the aforementioned dinosaurs and non-dinosaurs from the Bone Wars plus Tyrannosaurus rex, Brachiosaurus (now split into Brachiosaurus altithorax and Giraffatitan brancai; the latter of which is infinitely more represented under the B. moniker), Styracosaurus, Ankylosaurus, Parasaurolophus, Corythosaurus, Kritosaurus, Plateosaurus, Protoceratops, Struthiomimus, Ornithomimus, and the non-dinosaurs Rhamphorhynchus, Dimorphodon, and Archelon.

1970s: The Dinosaur Renaissance changed the image of dinosaurs to more active, more intelligent, more caring to their offspring, and well-adapted to their environment (and surviving extinction through bird descendants). Introducing: Deinonychus, and to some extent, Archaeopteryx (as a proper dinosaur; it's been well-known since the 19th century, but was considered a non-dinosaur before the Renaissance).

1980s/1990s/2000s: The original movie The Land Before Time and other works made in the second half of the 1980s started popularizing the image of dinosaurs as set up by the Dinosaur Renaissance. Since the 1990s, scientifically up-to-date books and computer animation in films/shows (especially in the Jurassic Park and Walking with Dinosaurs franchises) have completed the job. Introducing:

  • By the Jurassic Park franchise: Velociraptor, Spinosaurus, Dilophosaurus, Gallimimus, Compsognathus, Mamenchisaurus, Euoplocephalus, Carnotaurus, Maiasaura, and Albertosaurus.
  • By the Walking With docu series: Giganotosaurus, Argentinosaurus, Utahraptor, Ornitholestes, Torosaurus, Dromaeosaurus, Therizinosaurus, Microraptor, and the non-dinosaurs Liopleurodon and Deinosuchus.
  • By the The Land Before Time films: Pachycephalosaurus/Stegoceras, Saurolophus, and Hypsilophodon.
  • By the Disney's Dinosaur film: Oviraptor/Citipati , Stygimoloch, and Pachyrhinosaurus.
  • By others: Coelophysis, Baryonyx, Troodon/Stenonychosaurus, some alleged "biggest sauropods" (Supersaurus, "Ultrasaurus", "Seismosaurus"), Gorgosaurus, Herrerasaurus, Heterodontosaurus, Barosaurus, Cetiosaurus, Tarbosaurus, Tenontosaurus, Ouranosaurus, Scelidosaurus, Lambeosaurus, Lesothosaurus, Tuojiangosaurus, "Monoclonius", Pentaceratops, Pinacosaurus, Deinocheirus, Dracorex, Psittacosaurus, Polacanthus, Anchisaurus, Saltasaurus, Kentrosaurus, Centrosaurus, Chasmosaurus, Gigantoraptor, and the non-dinosaurs Quetzalcoatlus, Kronosaurus, Megalania, and Titanoboa.
    • Note: The number of asterisks and the Entry Time & Trope Maker are (or can be) kinda subjective, and the latest two do not refer to the scientifical discovery of the animals but to one of the first noticeable works in which they have been portrayed. For example, both Velociraptor & Spinosaurus were first discovered and described in the early XX century, but they have ascended to true Stock only in the last few decades thanks to one single series.

    open/close all folders 

Bipedal meat-eaters (usually)

Most dinosaurs were herbivorous or omnivorous; the Theropod group contains all the carnivorous dinosaurs. Some of them were very small, while the biggest weighed as much as an elephant or a bit more, and were taller and much longer. Their legs were birdlike in structure; their feet had three main toes and usually a smaller reversed forth toe. All of them (except perhaps Spinosaurus) were bipedal; some had only tiny rudimentary forelimbs. Theropods are the only group of dinosaurs that has living members today, since they included the common ancestor of birds. Some close-to-bird theropods became omnivores and sometimes herbivores; the group includes the only toothless non-bird-dinosaurs. Many theropods are now known to have been feathered, but in films they are usually shown with lizard-like scales, while documentaries tend to be a bit wonky on the coverings of their theropods.

    Great-stock theropods 

The King of the Cretaceous: Tyrannosaurus rex ***

Lived in western North America (between Alberta and Utah, and possibly as far south as Texas) 68-66 mya at the very end of the Age of Dinosaurs. Other tyrannosaurs lived in Asia in the same period, and other members of the tyrannosaurid family lived slightly earlier (still within the Late Cretaceous Period) in North America. note  Together with Triceratops (and few others), Tyrannosaurus was one of the rare dinosaurs that was directly led to extinction by the asteroid/comet collision at the end of the Mesozoic Era.

T. rex was discovered by Barnum Brown shortly before the start of the 20th century, and described by Henry Fairfield Osborn in 1905. Since then, it has been a hit with the audience and possibly the most famous dinosaur for almost a century. During this time depictions of the "rex" have changed from the heavy, fat-bellied giant with goose-like gait and flexible tail seen in Fantasia to the slender, running beast seen in Jurassic Park. We were waiting to see it, or at least its chicks, depicted with feathersnote , and recently this idea has been seeping into pop-consciousness (thank you Dinosaur Revolution, Dinosaur Island (2014), Pokémon, Mighty Magiswords, Saurian, and Doraemon).

Despite only living for a couple of million years in a small part of the world, every visit to a dinosaur-populated time or place will have at least one T. rex appearing. This is for reasons better explained on the animal's own trope page. Yes, that's how big it is in media.

  1. Entry Time: 1905
  2. Trope Maker: Itself

Sickle-feet: Deinonychus & Velociraptor, aka the "Raptors" ***

Raptors, or more formally dromaeosaurids, were bipedal carnivorous dinosaurs of the Cretaceous Period. They were small with long, thin tails and compact bodies. They were closely related to birds: their skeletal structure was bird-like, and since the late 1990s it has been proven they were also covered with pennaceous feathers.

The most distinctive feature, howewer, was the large "sickle claw" on their second toe. It was a very specialized tool, and has also been compared with the saber-toothed cats' fangs. The toe bearing it was very shortened and strong compared with the other two main toes. When walking and running dromaeosaurids kept their 2nd toe raised up to the ground level, so the whole weight of their body was substained by only two digits of each hindlimb. The sickle-toes were moved by powerful muscles and tendons; scientists think "raptors" were able to lower them when used as weapons, just like cats do with their retractable claws. How it was used is being still debated.note  For decades, dromaeosaurids were depicted as hunting and attacking herbivores much bigger than itself, e.g. the classic Deinonychus hunting Tenontosaurus or even the five-ton Iguanodon. Like a pack of wolves, dromaeosaurids were envisioned attack their prey en masse, using their powerful claws to rend and to climb atop the herbivore. Since around 2000, dromaeosaurids have instead been suggested to have been mostly solitary hunters, taking prey the same size or larger than themselves, but leaving the very large ornithopods or sauropods alone.

In the early 20th century, two small dinosaurs were discovered and described as generic small predators. Both were from the Late Cretaceous. While the finds were incomplete and difficult to interpret, we now know the animals were about 6.5 ft/2 m long and weighed about 33 lb./15 kg. Dromaeosaurus ("running lizard") lived in the Alberta region, while Velociraptor ("swift robber") lived in Mongolia and northern China 75-71 mya. For half a century, they were sorted away and largely ignored. Then...

Deinonychus note  ("terrible claw") was (re)discovered in 1964. It lived 115-108 mya in Early Cretaceous North America and was at the same time one of the largest and one of the earliest raptors, 11 ft/3.4 m long and weighing 160 lb/73 kg. Even though some illustrations showed it as tall as an adult man, it would actually only reach his hips if alive today. Some years later, more complete remains of Velociraptor were found, showing that it was similar to Deinonychus but even smaller (the weight of a large turkey).

Deinonychus was described by John Ostrom in 1969 in an influential monograph that kicked off the "Dinosaur Renaissance". After that, paleontologists, especially Ostrom's pupil Bob Bakker, began to debate if the traits ascribed to Deinonychus (agility, smartness, warm-bloodedness, social behavior) should be extended to all dromaeosaurids, or possibly to all theropods, or even to all dinosaurs. This debate continues still today.

In the 1980s, one paleontologist (Gregory Paul) claimed that Deinonychus and Velociraptor were actually the same genus and that the species Deinonychus antirrhopus should be renamed "Velociraptor antirrhopus"; author Michael Crichton picked up this idea, showing both Deinonychus and Velociraptor proper in his Jurassic Park novel as distinct species within one single genus, "Velociraptor". "Velociraptor antirrhopus", aka Deinonychus, is the main "raptor" in the story, while Velociraptor mongoliensis itself appears only in the shape of newborns. Being bigger and more menacing for humans, Deinonychus was the one chosen for the bad guy role, even though it's possible Crichton chose to name it Velociraptor just because he thought this name is cooler-sounding.

Works from before the 1970s never represent dromaeosaurids, simply because they were scientifically too obscure at the time. Significantly, between 1970 and the Jurassic Park mania in the 1990s, the most represented "raptor" (though not yet known by that term) in popular culture was the biggest known at the time, Deinonychus, while the less-impressive Velociraptor was totally unknown to laymen (not counting the antecedent dino-fans). For instance, see Dino-Riders, Carnosaur, the Rune Quest Borderlands tabletop RPG adventure, or even the Dutch metal-band named Deinonychus. It was Jurassic Park that apparently caused Velociraptor to displace Deinonychus as the stock sickle-clawed dino (even documentary media started showing the "veloci" more often thanks to the film), and started the usage of "raptor" for dromaeosaurid in the mind of the public — prior to this, "raptor" was used only to indicate Noble Bird of Prey. Without Jurassic Park, Velociraptor would have almost-surely remained in the Non-Stock realm forever. There are several issues with the depiction of raptors in the film.

At the same time that the name Velociraptor became popular, a new dromaeosaurid was discovered in Utah, that was named Utahraptor: see in another section for this one.

Speaking of Misplaced Wildlife, you can expect any of these three dromaeosaurids to be placed in the same habitat as at least Tyrannosaurus and Triceratops. In reality, Deinonychus and Utahraptor were already extinct by the time T. rex came along and Velociraptor lived on the other side of the planetnote . However, this inaccuracy was vindicated somewhat by the discovery of Acheroraptor (described in 2013) and Dakotaraptor (described in 2015), which greatly resembled Velociraptor and Deinonychus respectively, and the latter was roughly the size of Utahraptor.

According to the most recent research, actual raptor hunting tactics did not involve high-speed pursuits or using the claws to disembowel prey. What they did involve, however, was a ridiculous amount of Nightmare Fuel. Dromaeosaurs could only run at about 45 miles/hour for the faster species (Deinonychus and Velociraptor) and 20 miles per hour for the larger, more robust Utahraptor (this is still faster than any human), but they had Super Reflexes and superb Combat Parkour skills, able to leap, flip, dodge, and accelerate with shocking ease. They were good climbers, and their feathered wings probably helped them control their falls as well as muffling sound. The talons provided a near-unbreakable grip, and were used as grappling devices and stabbing weapons. Recent research into their eye sockets prove they had superb vision and were able to see very well in the dead of night, which was when they would use Jump Scare tactics to sneak up on unwary prey. Put together, they provide a frightening picture of an agile, stealthy, powerful hunter stalking victims at night from the treetops, completely silent and invisible, before leaping in as Death from Above, dodging counterattacks using Combat Parkour, latching on with a formidable grip, and either stabbing the prey in the neck or pinning it down and eating it alive as it writhed in agony.

  1. Entry Time: 1970s (Deinonychus); early 1990s (Velociraptor)
  2. Trope Maker: The "Dinosaur Renaissance" (Deinonychus); Jurassic Park (Velociraptor)

    Post-rex stock theropods 

Since the '80s/'90s, a handful of large theropods have started to filter into pop-consciousness, often after a single remarkable appearance in Movieland: Spinosaurus (Jurassic Park III), Giganotosaurus, Carnotaurus (Disney's Dinosaur), Baryonyx (Ice Age 3: Dawn of the Dinosaurs), and some non-rex tyrannosaurs. Despite having often some cool traits (crests, horns, claws, or sheer size), none of them has managed to replace T. rex as the "King Dinosaur" — at least for now. Though relatively small, Dilophosaurus (popularized by the 1st Jurassic Park film) is here for comparison.

Spiny-backed River Monster: Spinosaurus **

Lived in Northern Africa 112-97 mya, during the Cretaceous Period. At present, this is the biggest theropod; no other matches it in bulk, length and height.

Spinosaurus is one of the most recognizable theropods with its 7 ft/2.1 m-tall spines on its back. In the most common interpretation the spines form a "sail" similar to that of the non-dinosaur Dimetrodon. Some suggest that they instead supported a ridge, while others thought they came from another dinosaur altogether. A sail could have been useful as a thermoregulating device to prevent overheating and/or as a display tool (like Stegosaurus plates), and a ridge could have been for display, making the animal seem larger, as well as storing extra energy gained from the giant fish and other prey that Spinosaurus fed on.

Spinosaurus was first described in 1915 by a German paleontologist, but its remains are very scanty: its skull is incomplete, and we didn't have limb bones until very recently. The best spinosaur find was stored in a German museum, which was destroyed by accident during an aerial bombing in World War II. In older drawings Spinosaurus had a head like a generic "carnosaur"; today it is generally accepted that its head was similar to a crocodile's. Due to the fragmentary nature of its remains, the actual overall size is in debate; it was once thought the same length of an average Tyrannosaurus (40 ft/12 m), but many paleontologists wanted to set the length at 50 ft/15 m. Lack of real evidence for this left T. rex with the official record until the discovery of Giganotosaurus in the mid-1990s.

Meanwhile, the spinosaur remained an only-known-among-dino-lovers dinosaur. Then, in the year 2001, Jurassic Park III (which fans don’t really like to talk about but was nonetheless popular) changed this situation in a blink. This film introduced the spinosaur to the audience as "bigger and badder" than a Tyrannosaurus rex, and easily capable of defeating the latter in a fight. Many dino-fans complained that the JP spinosaur was oversized and altered to make it a sort of Pseudo-Rex thing. Then, new discoveries told us Spielberg wasn't totally wrong: Spinosaurus really was bigger than Tyrannosaurus rex, in fact larger than shown in the film. Not only that, it was indeed the biggest of the lot, and is still considered to be.

There is some controversy regarding Spinosaurus’ diet and way-of-life: did it prey on fish like its smaller cousin Baryonyx (see below), or on giant herbivores like Tyrannosaurus did? Experts tended to prefer the first option at the time Jurassic Park III was produced, and this fostered even more criticism about the film portrayal as the Ultimate Superpredator. Today Spinosaurus’s lifestyle is generally believed to have been midway between these two extremes: an opportunist like a giant, clawed, saltwater crocodile, attacking other smaller dinosaurs when given the opportunity, as well as eating giant fish (mostly sharks and other fish the size of most dinosaurs) and possibly crocodiles, a feat requiring tremendous levels of strength, and using its size to steal kills from other predators. We're unsure about the latter, though: Carcharodontosaurus was specially adapted to big-game hunting and could open its jaws very wide to inflict severe slicing cuts, which could likely cause the spinosaur to bleed to death if the two fought. Spinosaurus’ large size would, however, make it a hard target to bite for other predators.

In 2014, Spinosaurus received an almost-total makeover after new fossils were discovered. In addition to tiny pores in its skull that might have enabled it to sense underwater prey (which was already known by then), Spinosaurus also had a relatively small pelvis and short hind legs with flat — possibly webbed — hind feet, among other adaptations for a semiaquatic lifestyle — all in all showing a surprising degree of convergent evolution with the ancestors of modern whales. Unrelated to its amphibious makeover, its reconstruction also gives it a dip in the middle of its dorsal spines similar to that of its relative Ichthyovenator. It has been suggested that the hind limbs were scaled incorrectly but then the people who made the discoveries have responded putting these supposed corrections to doubt. Also, the tall spine on the sail might have actually been located further back on the body thus forming a more shallow and gradual version of the "classic" Spinosaurus sail note , although this too is debatable. Finally, it has been suggested that Spinosaurus held its neck vertically rather than horizontally. This would have shifted the center of gravity back and allow Spinosaurus to walk bipedally most likely similar to a duck.note 

Not all scientists are convinced, however, and a 2018 study has been released suggesting that, rather than being a full time swimmer, Spinosaurus spent most of its time wading along the shore and hunting fish in shallow water, more like a giant heron or stork than a crocodile. However, this study is not without a few issues, namely giving the tested Spinosaurus models with a more narrow torso due to basing it on reconstructions seen in lateral view.

  1. Entry Time: 2001
  2. Trope Maker: Jurassic Park III

Giant Predator of the South: Giganotosaurus *

Giganotosaurus (NOT "Gigantosaurus"; that name was used for an invalid sauropod) lived in Late Cretaceous South America 97 million years ago. A close relative of Allosaurus, it had a bigger head (6 ft/1.80 m long, even longer than a Tyrannosaur’s) and a stockier build: its looks seems rather like a cross between an allosaur and a tyrannosaur — incidentally, making the classic hybrid allo/tyranno so often seen in classic films (Fantasia, 1 Million B.C.… ) a sort of Truth in Television.

Discovered in 1993 and officially described two years later, Giganotosaurus was celebrated as "the biggest predatory dinosaur ever," surpassing Tyrannosaurus, of whom the largest specimen known (the famous Sue) was discovered a few years before. The "giga" remained the record-holder until new Spinosaurus fossils were discovered in the 2000s, and the re-examination of the descriptions of older finds reminded us that the latter was even larger, something already postulated but ignored for 80 years.

At the same time, re-examination of Giganotosaurus remains show an animal not much larger that Tyrannosaurus; the only advantage in length is due to a longer snout, and were the two animals placed side-by-side, they'd appear to be the same size. Its close relative Carcharodontosaurus (known since the first half of the 20th century in the form of teeth and some sparse bones, but rediscovered in 1996), got the same treatment in the 1990s, but ultimately lost the struggle for widespread recognition; and both ended up overshadowed in popular culture by Spinosaurus.

Giganotosaurus remains one of the most powerful meat-eaters that ever lived; and it's just starting to gain popularity. The fact that it could have possibly hunted some of the largest sauropods — possibly including of the utterly vast Argentinosaurus — means that it may become very popular in the future. If that doesn't sound cool enough, then consider that to do so, it would have had to be a pack hunter. Chased By Dinosaurs did a special on just how badass such a hunt would be (even though in the show the Argentinosaurus that became prey was a juvenile). Though there isn't any evidence for pack behavior in Giganotosaurus, there might be for its relative, the recently-discovered Mapusaurus, which was the same length but had a more slender frame.

  1. Entry Time: 1995
  2. Trope Maker: Dinotopia: The World Beneath

Meat-loving, sprinting bull: Carnotaurus *

Another South American theropod like the former, Carnotaurusnote  lived in the Late Cretaceous in a younger age, 70 million years ago. Discovered only in 1985, it is known from a single specimen, but this was one of these things every paleontologist wishes to find: one of very few big theropods so far found with skin impressions. As these prints are from the whole right side of its body, Carnotaurus is one of the only large dinosaurs whose external look is known with a reasonable degree of certainty, together with the so-called "hadrosaur mummies" (see "Hadrosaurs"). We don't know what was the coloration of the living animal, however.

Our carnotaur has also revealed to be one of the strangest-looking dinosaurs known. Forelimbs even tinier than those of T. rex, sort of useless stubs with no true fingers (though three clawed fingers appear in many portrayals, and sometimes even a small Iguanodon-like thumbclaw for each hand) that contrast vividly with the long legs apt for high-speed runs note . Unusually shortened head (some compare it to a bulldog's). Above all, a couple of unique bull-like horns above the eyes which no other known theropod had, not even its closest relatives (Carnotaurus means "meat-[eating] bull"). Finally, its skin was covered by rows of horny tubercles. The horns and the skin make Carnotaurus a quite dragon-looking dinosaur. Ironically, with its slender body, tiny forearms, and fragile lower jaws, it's hard to imagine how it could kill large prey in Real Life, especially if you think it doesn't come close to rivalling Tyrannosaurus in size (it was only about 22 ft/7 m or so in length, while a big rex would be about 43 ft/13 m). A clue may come from the fact it could have been the fastest non-bird dinosaur ever discovered, perhaps being able to run at 75 miles per hour. It has been suggested it ran into prey at full speed with jaws open, using its head as a sledgehammer.

Carnotaurus has become somewhat popular since the Nineties thanks to its striking look. Its most remembered apparition is in the 2000 Disney’s Dinosaur, where it's shown as an oversized, pseudo-rex villain. Here, the biggest carnotaur appears even larger than a spinosaur, able to lift an Iguanodon with its jaws, and fling it to death against a rock. In Real Life the 1-ton Carnotaurus was much smaller and weaker than the 5-ton Iguanodon, and lived several million years after the latter. Before that, it also showed up in Michael Crichton's second Jurassic Park book, where its size was portrayed more accurately, but to up the threat level, it was given (quite implausible) chameleon-style stealth abilities. Note that neither modern birds nor crocodilians can change their colors like chameleons do. Finally, it has recently made a cameo in 2018's Jurassic World: Fallen Kingdom.

Carnotaurus may be the responsible for the recent decline of the classic carnivore Ceratosaurus in media, as both dinosaurs had a similarly horned/tubercled look and the two dinos might be confused with each other, even though their look was rather different (see also Ceratosaurus in another section). But also note a bit of resemblance both in shape and in name between the carnotaur and a mythical critter, the Minotaur. This association may have at least subconsciously led to it becoming a go-to bad guy dinosaur.

  1. Entry Time: 1995
  2. Trope Maker: The Lost World (1995) (novel)

Heavy-clawed, croc-mouthed fisher: Baryonyx *

This is a cousin of Spinosaurus that lived in Europe in the Early Cretaceous, 130-125 mya, alongside Iguanodon. Discovered in 1983 in Southern England and named in 1986, its find got massive media coverage at the time, especially in the British media; in part because, being 30 ft/9 m long, Baryonyx was the largest and most complete European giant theropod, but mostly because it was very different from other dinosaurs known at the time, with its crocodile-like jaws lined with an incredible 96 teeth note  (Spinosaurus was still portrayed with a token-theropod head in the 1980s and '90s), and very special forelimbs.

Baryonyx means "heavy claw" and the animal has been nicknamed "Claws" because of its 10-inch/25-cm hook-like thumb-claws, bigger than the other two fingers on each hand. We don't know if Spinosaurus had these hook hands as well. Baryonyx’s forelimbs were longer and stronger than in most other theropods, but the structure of the forefeet seems to preclude quadrupedal walking (contrary to what is sometimes shown in illustrations); it is speculated, however, that Baryonyx might have fed by resting on its front legs on a riverbank and sweeping large fish such as the carp-like Lepidotes from the river with its powerful claw, a bit like grizzly bears do with salmon. We know for sure fish were included in its diet: scales of Lepidotes were found inside the ribcage of the original (and only sure) Baryonyx specimen.

Baryonyx was the first discovered fish-eater among dinosaurs, and several traits scientists today assign to Spinosaurus were initially based on Baryonyx. Together, these dinosaurs (plus few others) form the spinosaurid family. However, "Claws" was quite different from Spinosaurus: it had no sail on its backnote , and was considerably smaller (10 m long and weighing 2 tons, like an Allosaurus). Its head was thinner with a small bump on its top, and gharial-like jaws with twice the teeth of most other theropods. Baryonyx has traditionally believed more aquatic than Spinosaurus: fish might have made a greater part of its diet, possibly with occasional carrion and small land animals as a supplement. Its short hindlegs show it was not an especially fast runner; moreover, its blunt croc-like teeth and weak thin jaws probably prevented the "bary" to kill prey the size of a fully-grown Iguanodon in spite of the former's huge thumbclaws (incidentally, Iguanodon too had oversized thumbnails, but they were almost-straight and not curved like the carnivore's).

Since the 1980s, Baryonyx has been one of the most frequently-portrayed large theropods in popular dino-books. On the other hand, it has long been ignored in Fictionland and even most TV documentaries.note  It came into the spotlight in 2009 thanks to the Ice Age 3: Dawn of the Dinosaurs film. Here an oversized Baryonyx called Rudy is the pseudo-rex Big Bad who is even bigger than the ''JPIII'' spinosaur or the real-life one. The baryonyx is unnamed however (some dino-fans wrongly think he's a Suchomimus), and also quite inaccurate, with a head shaped like a literal crocodile's and hands lacking the distinctive thumbclaws. Rudy is an albino; unlike chameleon-like carnotaurs, albino dinosaurs were possible in Real Life but probably very rare, and the predatory ones shouldn't have been good hunters because of their non-mimetic color and eyesight problems. In 2018,the Jurassic Park franchise added the baryonyx as one of the starring animals in its 5th movie.

  1. Entry Time: 2009
  2. Trope Maker: Ice Age 3: Dawn of the Dinosaurs

Smaller Tyrannosaurs: Albertosaurus and Gorgosaurus *

It's Albertosaurus, and not Tyrannosaurus rex, the most abundant tyrannosaurid in fossil record, and it's also the second big-sized theropod by wealth of fossil material, just after the unbeatable Allosaurus. And yet, Albertosaurus has not gained much attention in films and comics as Tyrannosaurus — tyrannosaurids are so similar to each other that if one appears in cinema, people will always call it T. rex. To compensate, Albertosaurus is a very common sight in many paleo-books, just as common as several Great- or Middle-Stock theropods.

Like Tyrannosaurus, Albertosaurus is portrayed as the superpredator of its time, North America 71-68 million years ago, 5 million years before T. rex. The menu of an Albertosaurus was probably not monotonous; several kinds of herbivores roamed North American plains at the time, from ceratopsians to hadrosaurs, from the armored ankylosaurs to small swift ornithopods and ornithomimids. Even though tyrannosaurids are classically shown battling some powerful prey, they more probably hunted young individuals more often, to avoid the risk of fatal injuries or consequent infections.

Compared with the legendary Tyrannosaurus rex, Albertosaurus was like a leopard compared with a lion; smaller (30 ft/9 m long against the 40 ft of T. rex), it was also more slender, with longer, thinner jaws, smaller teeth, and more agile legs apt to higher top speeds than Tyrannosaurus. It had also small but distinctive "horns" above its eyes; one could thus say it was a tyrannosaurid version of Allosaurus. Even the herbivores which shared their world were matched with tyrannosaurids; those which lived alongside T. rex were bigger, slower and more heavily armored than those living with Albertosaurus.

Albertosaurus was also the first dinosaur ever discovered in Canada, at the end of the 19th century, but was named only in 1905 (incidentally, the same year as Tyrannosaurus) after the Canadian province of Alberta, where most of the abundant Canadian dinos have been discovered. Albertosaurus has also contributed indirectly to the popular image of tyrannosaurs. The forelimbs of Albertosaurus have been known since its very first find, while those of T. rex were first discovered only in the 1990s; for almost a century the well-known two-fingered hands of "rex" have been modeled upon those of Albertosaurus, debunking at the time the old pop-cultural Hand Wave about portraying three-fingered tyrannosaurs. note 

Discovered in 1914, Gorgosaurus is another North American tyrannosaurid which was long considered a distinct genus compared to Albertosaurus. Then, in the 1970s, Canadian paleontologist Dale Russell found the two animals so similar they had to been put under a single name: since the first created name always has priority, so was Albertosaurus. Only in recent years, scientists changed idea again separating "Gorgosaurus" from "Albertosaurus" — the whole process is always quite arbitrary in paleontology, never forget this. There has also been a curious sequence in pop-portraits: Gorgosaurus has long been the most depicted non-"rex" tyrannosaur in classic paleo-art and old books, also thanks to a famous painting made by Czech paleoartist Zdenek Burian in the 1910s which started the trope; then, its long-lasting synonimization with Albertosaurus harmed its relevance, and today Albertosaurus is usually regarded as the new prototypical “small” North American tyrannosaur. But in 2013, Gorgosaurus made its way into cinema by playing the main antagonist of the Walking with Dinosaurs.

  1. Entry Time: 2000s (Albertosaurus), 2013 (Gorgosaurus)
  2. Trope Maker: Jurassic Park: Trespasser (Albertosaurus), the Walking With Dinosaur film (Gorgosaurus)

The Myth's Twin: Tarbosaurus *

Tarbosaurus bataar means "Mongolian alarming lizard". If you want to describe it, don’t worry, it’s a simple thing: just say it was the Asian twin of Tyrannosaurus rex and you’ve given the idea.

To be more accurate, Tarbosaurus was slightly smaller than Tyrannosaurus, with a larger head and a slightly lighter trunk, but shared with the "rex" the same familiar body-shape. Its forelimbs were identical to T. rex but a bit smaller, sometimes cited as “the smallest arms in the dinosaur world” - even though the “horned” theropod Carnotaurus had even more reduced arms, as did some flightless birds like the recently-extinct Moas (see below). Tarbosaurus was the "king" of the predators in its habitat, Late Cretaceous Asia, just like T. rex in North America. These two dinosaurs are so similar, that some scientists suggested in the past that Tarbosaurus is another species of the genus Tyrannosaurus (Tyrannosaurus bataar), but new studies seem to disagree. Maybe some smaller North American tyrannosaurs were closer to T. rex than Tarbosaurus. The tarbosaur may be closest to Zhuchengtyrannus, an Asian tyrannosaur named in 2011, while "Jenghizkhan" (from the Mongolian Gengis Khan), described in 1995, is today just an invalid synonym of Tarbosaurus.

Note that while Tarbosaurus was very similar to T. rex, it wasn't identical, and there were differences that inexperienced writers and artists often miss. For example, Tarbosaurus had a narrower, less powerful skull, a unique locking mechanism, less-binocular vision, and smaller but sharper and more serrated teeth than its American cousin, suggesting it was not as adapted to feed on armored prey like ceratopsians and ankylosaurs, and instead favored preying upon large hadrosaurs.

Tarbosaurus has been first discovered in 1955 in Mongolia, more precisely in the Gobi Desert. Mongolia, a sparsely populated Asian country bordered by Russia and China, has always had a major role in the brief history of paleontology: despite being much smaller than China, Canada or the USA, it has given us the same number of fossils of the latter, almost all from Late Cretaceous. Among them, most of the classic Asian dinosaurs: from the famed Protoceratops/Velociraptor battle to the first Mesozoic dinosaur eggs ever discovered, from oviraptorids to the huge Deinocheirus, from the duckbilled Saurolophus to the ostrich-like Gallimimus to the "parrot dinosaur" Psittacosaurus, ankylosaurs like Pinacosaurus, titanosaur sauropods, small pachycephalosaurs, the birdlike Avimimus, Segnosaurus, Saurornithoides, Mononykus, and the scythe-claws of Therizinosaurus. Interestingly, the succession of geological periods (Cretaceous-Jurassic-Triassic) of the Mesozoic era, have also a distribution in latitude which is amazingly specular in Asia and in North America. In both continents, the Cretaceous terrains are those in the northern part of the range (Alberta, Canada/Montana, USA, and Mongolia/Inner Mongolia/Northern China); the Triassic terrains are the most southern (Arizona/New Mexico, USA, and the province of Yunnan, southern China); while the Jurassic one were in the middle (Utah/Colorado/Wyoming, and the province of Szechuan, central China). Also note that most North American dinosaurs have been discovered in western USA and western Canada (not in the coastal region however, but only in the Mountains and Plains); while the Asian dinosaurs are concentrated in only two countries, Mongolia and China, both in the Far East.

  1. Entry Time: 2003
  2. Trope Maker: Chased By Dinosaurs

Slender, double-crested ancestor: Dilophosaurus **

Dilophosaurus lived 197 million years ago in Early Jurassic North America. It was one of the first theropods to have exceeded human size (20 ft / 6 m long and weighing 500 kg). Smaller and more slender than the other carnivores listed above, it was a fairly close relative of the dog-sized Coelophysis.

Its most easily recognizable trait is the two parallel crests on its skull (perhaps occurring only in males), probably used for display. These fragile and vulnerable structures indicate that it was no badass dinosaur. Its head was long and narrow with weak jaws and teeth, and the upper jaw also had a deep indentation on each side near the tip of the snout, making the whole structure even weaker.note  Scientists have usually said the dilophosaur was a mere scavenger or a small prey hunter, even though some had initially described it as the "the first giant killer dinosaur". It was indeed one of the biggest terrestrian carnivores of its time (some docu-portrayals show it as a rather unlikely powerful super-predator); however, really powerful meat-eating dinosaurs only started to appear in the Middle Jurassic, for example Megalosaurus. note 

Dilophosaurus was first described in 1954 in Arizona from scant remains lacking the head, and was initially thought to be another species of the "wastebasket taxon" Megalosaurus. The first head complete with double crest was found only several years later; in 1970, the animal received the name Dilophosaurus, "double-crested lizard". Several footprints found in Early Jurassic terrains of the USA might have been made by dilophosaurs, but the exact identity of dinosaurian tracks cannot be told with certainty. One of these tracks was made by a swimming animal which barely touched the bottom with the tips of its feet.

It's unlikely that many people outside the dino-fandom had ever heard of Dilophosaurus before the novel Jurassic Park was published in 1990. Here it was depicted as capable of spitting venom like some species of cobra, which it probably couldn't do in Real Life: venomous saliva is unknown among modern birds and crocodiles.

Two years later, the JP movie made the dilophosaur even more popular and even more incorrect. Its size was greatly decreased note , but above all, Spielberg added a totally improbable Frilled Lizard-like cowl on its neck. It certainly did not have this frill; it would require a lot of specific musculature on the neck, and the imprint of this would be visible on the skeleton (it isn't). Still, most later popular depictions have represented Dilophosaurus with this thing.

Just like Velociraptor, Dilophosaurus became a household name after the film, commonly known as the Spitting Dinosaur. Even though it has not appeared in any of the sequels (except for a quick cameo as a hologram in Jurassic World), the JP portrayal has remained in pop-consciousness, coincidentally preventing the Real Life animal from become more widely-known. Today, the ever-increasing public interest in dinosaurs (mainly started thanks to Jurassic Park) is making Spielberg’s Mix-and-Match Critter more and more of a Lost Subtrope.

  1. Entry Time: 1990
  2. Trope Maker: Jurassic Park (novel)

    Pre-rex stock theropods 

Some large meat-eaters entered pop culture before T. rex: Allosaurus, Ceratosaurus, and Megalosaurus. But they have been less frequently portrayed since T. rex was discovered.

The King of the Jurassic: Allosaurus **

Allosaurus lived 155 to 150 million years ago in North America, with some fossils found in Europe and maybe Africa. Along with Tyrannosaurus, it has traditionally been the large carnivorous dinosaur. Allosaurus is the scientifically most well-known large theropod: dozens of specimens have been found so far in Western USA, including a veritable "graveyard" in the Cleveland-Lloyd Dinosaur Quarry (Utah).note  Many young individuals are also known, but not nests or hatchlings.

First discovered in 1877 during the Bone Wars, Allosaurus literally means "other lizard" or "strange lizard", but Othniel Charles Marsh's article naming it gives no reason for the bland choice. The most well-known species is Allosaurus fragilis ("the other fragile lizard"); some fragmentary remains of unusually large size are often classified in separate genera (see Prehistoric Life). Some scanty fossils from Early Cretaceous Australia used to be classified as a small-sized late-surviving Allosaurus species, but were reclassified in 2009 as a totally different theropod, Australovenator. Even scantier remains were found in the USA before Allosaurus was officially described in 1877; they were labeled Antrodemus, but possibly belong to Allosaurus as well. If true, the former might become the valid name for this dinosaur (the name "Antrodemus" appears sometimes in old dinosaur books instead of "Allosaurus").

Allosaurus was the top predator in the Late Jurassic, sometimes referred as "the tyrannosaur of the Jurassic". Its hunting behavior is still uncertain: we're not sure if it was mainly a pack-hunter or a solitary ambush-predator. In documentaries and pop-books it usually appears as a pack-hunter capable of bringing down the biggest sauropods like Diplodocus (like in the memorable The Ballad of Big Al), Apatosaurus, or even Brachiosaurus. Alternatively, it is shown in a battle against the armored Stegosaurus (the Jurassic equivalent of the Tyrannosaurus-vs-Triceratops Cretaceous duel). All this might be Truth in Television since all these animals lived together in North America in the same period, but more probably Allosaurus more often hunted easier prey such as young sauropods, young stegosaurs, and ornithopods like Camptosaurus, because its jaws and teeth were less-powerful than those of the tyrannosaurs. There are, however, stegosaur and sauropod fossils showing Allosaurus bite marks and Allosaurus fossils that show wounds created by stegosaur tails, showing that allosaurs could have been predators as powerful as the more evolved tyrannosaurs.

Allosaurus entered pop culture before Tyrannosaurus rex. After its description, it was briefly considered the "biggest land carnivore ever" together with Megalosaurus. In Conan Doyle’s The Lost World (1912) the two scientists encounter a giant carnivore, and argue about whether it is an Allosaurus or a Megalosaurus (maybe a reference to the then-recent Bone Wars). Soon afterward, both dinosaurs got overshadowed by the more impressive (and much cooler-named) Tyrannosaurus in pop-media, especially cinema. Allosaurus has somehow managed to survive the supremacy of the rex... automatically becoming its Poor Man's Substitute, as the two animals tend to be easily confused with each other in the public mind.

Actually, Allosaurus is rather easy to distinguish from T. rex. It was generally smaller (the classic species was slightly shorter and about one half of the weight of a T. rex), had shorter legs, a longer tail, slimmer body, longer neck, narrower head, weaker lower jaw, smaller teeth, and a pair of "bosses" in front of its eyes (maybe covered in keratin in Real Life, making them like small "horns"). Above all, it had longer front arms with three clawed fingers rather than two. Sadly, all these differences tend to be glossed over in popular media. The fact that T. rex itself has often been depicted with long arms with three functional digits (e.g. in Disney's Fantasia) doesn't help, either.

Among the official Allosaurus appearances in cinema, the Ray Harryhausen ones are the most remembered. The allosaur is the go-to Big Bad of his movies, appearing in One Million Years BC and playing the role of Gwangi in The Valley of Gwangi. Ray's critters looked just like that of Fantasia, with the same mishmash of allosaur and tyrannosaur features (and with the same outdated erect body, serpentine tail and goose-gait); the only difference is that Harryhausen's theropods have Evil Eyebrows — this may be forgivable for some, considering the aforementioned eye bosses wich could have given to it a "fierce look" like an eagle.

  1. Entry Time: 1912
  2. Trope Maker: The Lost World

Horned rex or underdog?: Ceratosaurus *

Ceratosaurus lived in the same places as Allosaurus in the Late Jurassic, 153-148 mya. Usually 17-23 ft/5-7 m long, it was smaller than most other Stock Theropods above, but still a powerful animal.

Its look was like that of an undersized allosaur, with the same eye-bosses and long forelimbs. Its name, "horned lizard", underlines its more distinctive anatomical feature: a laterally flat crest on its nose, classically described as a "nasal horn". note  It was also the only known theropod to have armor in the form of bony plates along the middle of its neck, back, and tail. While the "horn" is the hallmark in every Ceratosaurus portrayal (don't be surprised to see it shaped like a rhino's), the armor can be left out altogether, or alternatively, modified to make the animal similar to a dragon.

Despite its appearance, Ceratosaurus was actually more archaic than Allosaurus. Allosaurus belongs to the tetanuran branch of theropods, while Ceratosaurus is the namesake of its own branch, ceratosaurs. The latter can be told apart from tetanurans by the primitive shape of their pelvis, more flexible tails, and a remnant forth finger on each hand (tetanuran theropods never have more than three fingers). Most of the other theropods discussed in Stock Dinosaurs are tetanurans, except fellow ceratosaur Carnotaurus, and the more primitive Dilophosaurus and Coelophysis.

Ceratosaurus was first found during the Bone Wars like Allosaurus, but is much rarer in the fossil record than the latter: many paleontologists suspect it was more solitary than allosaurs. In paleo-art and documentaries, Ceratosaurus can be shown either as a scavenger / an underdog predator, or as a pack-hunter of big game. While Allosaurus is seen as the "lion" of its time, Ceratosaurus might be considered the "hyena"; with its smaller size, longer teeth and stronger jaws, the comparison works. Since Real Life spotted hyenas are not lions' underdogs (as seen in The Lion King) with both co-dominating the top-predator niche, its possible that ceratosaurs and allosaurs had a similar relationship, but remember that comparing dinosaurs with modern mammals is always problematic in paleontology.

The horn on its nose and the armor make Ceratosaurus the most "dragon-looking" of the theropods known at the start of the 20th century. It's not a big surprise that it appeared in so many classic dino-films, from simple cameos (like Fantasia) up to being the main dino-actor, like the Ray Harryhausen film Animal World, in which two ceratosaurs get into a fight and fall off a cliff. Ceratosaurus holds the record of being the first dinosaur ever shown in non-animated cinema — the 1914 film Brute Force pitted cavemen vs dinosaurs and started the Dinosaurs Are Dragons trope. In later fiction Ceratosaurus received the same treatment as Allosaurus, acting as a T. rex substitute for the Big Bad part. With its distinctive look, Ceratosaurus is less likely than Allosaurus to be confused with Tyrannosaurus; on the other hand, its size is often exaggerated to make it more of a "horned tyrannosaur".

Ceratosaurus is quite rare in films these days: the only recent example is a short cameo in Jurassic Park III, in which it's not even named (but at least is correctly sized).note  Even modern documentaries rarely represent it — the Walking with Dinosaurs series didn't show it at all. The recent Ceratosaurus decline is probably due to the occurrence of other, newly-discovered theropods since the '70s: Carnotaurus in particular, being similar yet even more badass looking.

  1. Entry Time: 1914
  2. Trope Maker: Brute Force (film)

The first named non-bird dinosaur: Megalosaurus *

We've already mentioned Megalosaurus more than once. Why? Well, both because it was the first giant theropod known to science, and because shows neatly how Science Marches On is normal stuff in dino-science.

Its first remain, the extremity of a leg-bone found in 1676 in England near Oxford, was mistaken by Robert Plot for the remain of an ancient giant man (others named this remain Scrotum humanum because of its shape), but this fossil has since been lost. Later, a half lower jaw with a single large tooth left was found in 1824 in Southern England; its discoverer, reverend and geologist William Buckland, described it as belonging to a "big lizard" (the meaning of its name, which started the tradition of "saurus" in dinosaur names). Buckland didn’t realize he had named the very first non-avian dinosaur. At the time, the Dinosaur category didn't even exist in scientific literature.

The scientific and popular view of what a megalosaur was has gone through several drastic changes. The first attempt at reconstruction, the life-size sculpture in Crystal Palace Park constructed in the 1850s, made the Megalosaurus a dragon-like animal walking on all fours. Next to the Megalosaurus was an Iguanodon sculpture (also quadrupedal), and for several decades this was the stock image of the world of dinosaurs: one herbivorous dragon facing a carnivorous dragon in combat. From this time is Charles Dickens' novel Bleak House (1853) where Megalosaurus is mentioned, described as an "elephantine lizard".

New genera of large carnivores were described during the Bone Wars, such as Allosaurus and Ceratosaurus, whose more complete remains showed clearly bipedal animals. Since then, Megalosaurus has also been reconstructed as bipedal. Even with their correct shapes, the "Megalosaurus vs Iguanodon" battle has remained a classic in non-fictional portrayals (a bit like "Tyrannosaurus vs Triceratops"), even though in Real Life the megalosaur was a middle Jurassic animal (166 mya), while the iguanodont lived 40 million years later in the Early Cretaceous.

The tendence to classify theropod fossils of every kind as Megalosaurus started soon after its first description. After the Bone Wars, Megalosaurus still remained a "Wastebasket taxon" to which all finds that were too incomplete or too ambiguous were assigned. Megalosauruses cropped up everywhere from North America to Africa and from Early Jurassic to Late Cretaceous. Finally, scientists sorted out outsiders into more than 20 genera (Carcharodontosaurus, Dilophosaurus, Eustreptospondylus, Majungasaurus, and Proceratosaurus among them). This cleanup has yet to be finished.

The only-valid Megalosaurus is a fairly generic theropod some 30 ft/9 m in length, similar to an elongated allosaur but smaller and more primitive. Some old popular portraits represent it as very massive and powerful, hunting alone even giant sauropods like Cetiosaurus. Even though its historical relevance makes it a common sight in classic and modern dino-books (expecially common are the photos of its original jaw), the "big lizard" didn't go a long way in popular works after the two important mentions in early literature (Bleak House and The Lost World). In the 20th century it heavily suffered the competition with Tyrannosaurus and Allosaurus — and the resolution of the "wastebasket" issue made the case against it even worse. Apart from some occasional documentary like Walter Cronkite 's "Dinosaur!", you have little chance of seeing any megalosaur either in cinema or in TV media — just as an example, Walking with Dinosaurs chose to portray the contemporary close-relative Eustreptospondylus in the Jurassic Europe episode. There is, however, the curious case of the TV show Dinosaurs, which has one "megalosaur" in the form of Earl Sinclair: but he doesn't look particularly like any dinosaur at all.

  1. Entry Time: 1854
  2. Trope Maker: Crystal Palace Park

Other large theropods

Sorry, these ones aren't here. If you're looking for Megaraptor, Suchomimus, Majungasaurus, and others, see here.

    Bird-like / small theropods 

Several bird-like and/or small theropods make appearances in media, although less commonly than the iconic "raptors".

Toothy Bird or Winged Dino?: Archaeopteryx, aka the "Missing Link" **

Archaeopteryx note  lived around 150-148 mya in Late Jurassic Europe. Its name means "ancient wing" or "ancient feather"; another obsolete synonym very common in old textbooks was Archaeornis, "ancient bird". Both terms are very meaningful about its historical relevance. And it is even sometimes known as the "Urvogel", which is German for "original bird" — it's rare that a dinosaur receive a common name that is not a mere translation of the scientific one, unlike Ice Age mammals.

Archaeopteryx was discovered 1861 in the famed Solnhofen deposit in Germany, whose rocks have preserved fossils so well that even soft parts of animals are visible. Because of this, most specimens of Archaeopteryx found later in Germany were found with impressions of feathers. Charles Darwin had published On the Origin of Species two years earlier, and in the following debate this "half-reptile, half-bird" became a key piece of evidence, as the perfect example of a "missing link" between two animal classes.

A century later, Archaeopteryx was again used as crucial evidence, this time in John Ostrom's theory that modern birds had evolved within the theropod group. Before that, most scientists considered Archaeopteryx and its bird-descendants only distant relatives of dinosaurs, in part because in traditional zoology Feathers = Bird, and no other dinosaur was known with imprints of feathers. Even though one scientist (Darwin's pupil T.H. Huxley) already recognized the dinosaurian origins of birds as early as the late 19th century (by studying the skeletal features), this was largely accepted only after the Dinosaur Renaissance note  and definitively proven only in the 1990s after the find of the feathered "Liaoning theropods".

Archaeopteryx has had a somewhat unique role among stock prehistoric animals: just like the Dodo is the icon of Extinction, Archaeopteryx has been that of Evolution. Within the long-lasting debate between scientists and creationists, the latter went so far to claim Archaeopteryx fossils are just fake.

According to modern knowledge Archaeopteryx is just another feathered theropod — possibly a bird, possibly a deinonychosaur, possibly more primitive than either. Highlighting its theropodian nature, one archaeopterygid skeleton with no signs of feathers was long classified in another theropod genus, Compsognathus (see later). The size of a chicken, Archaeopteryx had a long bony tail (modern birds always have stubby tails), three claws on its forelimbs, running feet with an enlarged second toe claw (this was discovered only in the 2000s), jaws with small, pointed teeth, and feathers. The main difference is that its feathers aren't just skin-covering down; it has flight feathers of very modern-looking shape on its wings and tail. It probably could glide but it is unlikely that it could flap its wings for powered flight — it didn't have the modern birds' keeled breastbone for powerful wing muscle attachment, but the usual "ventral ribs" seen in non-bird theropods. Maybe it simply used its claws to climb up trees and then glided to the next tree. Its diet probably consisted only of insects and small vertebrates, but no stomach contents are known; also, we don't know how it mated or if it cared its offspring.

Its classic status as "the first bird" is merely traditional at this point, and the start of the "bird lineage" within the theropod branch depends on the chosen criteria to define what’s a bird and its exact position. Still, it remains one of the most ancient known dinosaurs found with imprints of feathers.

In media, Archaeopteryx is well-established as the "first bird". It will sing like a bird and perch like a bird, neither of which was possible for the real-life Archaeopteryx; expect it to fly too, though later studies showed that, though it could fly, it likely wasn't very good at it and only did so in times of emergency or when it was convenient—these studies revealed that its flight patterns would've been fairly similar to a modern pheasant. Media archeopteryges will lack the sickle claws on their feet, and possibly also their wing-fingers and teeth. Expect also to see them with naked heads, making them resemble feathered lizards. Actually, their heads would have been almost totally feathered like deinonychosaurs and most modern birds (see Raptor Attack).

  1. Entry Time: 1861
  2. Trope Maker: Darwin's On the Origin of Species

Lighter and Fluffier Dinos: Ornithomimus, Struthiomimus & Gallimimus **

Before Jurassic Park made the "raptors" popular in The '90s, ornithomimids used to be the animals that most often came to mind to people when thinking about small & agile dinosaurs, as the antithesis to the classical Mighty Glacier image.

Ornithomimus, the prototype of the family, lived in North America between 75-66 million years ago, in the Late Cretaceous. It was 12 feet/3.5 meters long and weighed around 220-330 lbs/100-150 kg. Its shape was similar to a long-tailed ostrich. It had a long neck with a birdlike skull and a toothless beak. The brain and eyes were large, possibly an adaptation to support quick movement. Its body was short and compact, like that of a bird. Its tail was very long, balancing the animal when running. The legs were similar to modern running birds, with short muscular femurs, elongated tibias/shins, and three toes each. With this anatomy it may have been the fastest non-avian dinosaur, easily capable escaping the bigger and clumsier Tyrannosaurus rex. Ultimately confirmed to be feathered, which was already suspected for some time.note 

As said above, Ornithomimus ("bird-mimic") is the prototype of the Ornithomimids, often nicknamed "Ostrich-dinosaurs". This family also includes Struthiomimus and Gallimimus among the others. The former ("ostrich-mimic") was almost identical to the namesake of the family (it had only longer forelimbs and bigger hands and claws), was just as fast and quick, and lived in North America in the same period (the two were actually considered the same animal at the time ornithomimids first entered pop-media, in 1940). They were definitively recognized as distinct only in the 1970s. The genus Dromiceiomimus ("emu-mimic") was briefly separated from Ornithomimus in the same decade, but has since been merged back in the 2000s.

As their names suggest, Ornithomimus and Struthiomimus have been recognized as birdlike dinosaurs since their very first discovery. Ornithomimus was the first described (USA, 1890, during the Bone Wars), while Struthiomimus was named later (Alberta, 1917). The first U.S. remains were fragmentary, though, and complete ornithomimids came to light only in the early 20th century. They were described as fast-moving and graceful even before the Dinosaur Renaissance, and usually portrayed with erect tail and horizontal body, unlike the giant bipedal dinos with their upright bodies and dragging tails.

Unusually for dinosaurs, media have never shown ornithomimids as scary killers dangerous to humans. This can be due to their lack of teeth that make them look harmless. Their actual diet is still uncertain, as no stomach remains are known for now. Their large numbers, among other things, seems to indicate that they were mainly herbivorous with insects, eggs, and small animals as a supplement. In popular media they have often been depicted as plant-eaters and/or insect-eaters (very rarely as meat-eaters). But the most common pop-portrayal has shown them as egg-stealers outwitting larger dinosaurs, like in The Land Before Time. Even though they might have eaten some eggs, there is no evidence this was a major part of their diet. Furthermore, not being maniraptorans ("robbing hands"), they probably couldn't grasp things so easily as the latter did. Today, the "robbing" role is more often attributed to the true maniraptoran oviraptorosaurs (see below). Finally, in the early 2000s it was suggested ornithomimids were filter-feeders like flamingos (as seen in Prehistoric Park), but now this hypothesis is disproved.

Discovered in the 1970s, Gallimimus ("rooster-mimic") was one of the largest ornithomimids — 20 ft/6 m long, with some reports of sizes up to 8 meters long, as long as a giant theropod like Albertosaurus. It lived in Mongolia in the late Cretaceous, 70 mya. Apart from its longer, blunter snout and slightly shorter legs, its appearance was that of an enlarged Ornithomimus or Struthiomimus, with small short forelimbs more similar to the former than to the latter. With its large fossil record Gallimimus has become a common sight in dino-books since the '80s, and entered the pop-consciousness after Jurassic Park — the film, not the novel, which has Hadrosaurus in the stampede scene. Like Velociraptor and Dilophosaurus, Gallimimus became one of the Stock Dinosaurs immediately after the movie, but has replaced Ornithomimus and Struthiomimus in pop-culture only partially. Fictional works from after 1993 can still add Ornitho- or Struthio- (or even "Dromiceio-") to their -mimuses, instead of Galli-.

  1. Entry Time: 1940 (Ornithomimus/Struthiomimus); 1993 (Gallimimus)
  2. Trope Maker: Fantasia (Ornithomimus/Struthiomimus); Jurassic Park film (Gallimimus)

Dinosaurs as pets: Compsognathus **

Compsognathus was native to Europe 150 million years ago and lived alongside the famed "first bird" Archaeopteryx, in the same habitat made of small islands. Like the "Urvogel", it was one of the first dinosaurs described, in the same year as the latter. The first Compsognathus specimen was found in Germany in the Solnhofen site (like Archaeopteryx). The second known specimen was found later in Southern France. Both skeletons are nearly-complete and still-articulated (again like Archaeopteryx), but haven't preserved imprints of skin. Though little-known, Compsognathus may have been the first non-bird dinosaur ever found from an almost-complete skeleton.

Only 4 ft long and weighing few kilograms, Compsognathus is the smallest Stock Dinosaur, not counting Archaeopteryx (and Microraptor, which has to be considered a real stock at this point). Like Coelophysis below, its frame was that of a generic small theropod with no sickle-claws on its feet. Compsognathus was more evolved and bird-like than Coelophysis however, with a shorter head and neck, a more compact body, and only three fingers on each hand. Old portraits in popular dino-books have typically depicted the "compy" with two-fingered T. rex-like hands, and sometimes even with fin-like hands: these errors were due to the incompleteness of the two known specimen's hands.

If you hear about it in documentary media, it will likely be for two things: its former record of "the smallest dinosaur" (classically described as chicken-sized because its first-found skeleton was only 2 ft long, but was from a subadult), and its former status as "the closest relative of Archaeopteryx" (despite similarities, it was possibly less close to birds than tyrannosaurs). Another compsognathid, Sinosauropteryx from Early Cretaceous China, shows downy covering around its skeleton but not pennaceous feathers; this was probably the same for Compsognathus, too.

Compsognathus has always been a regular sight in dino-books, in which is usually shown as a solitary hunter of insects, small vertebrates, and sometimes adult archaeopteryges (that last depiction is unlikely though).note  Even though its tiny size doesn't make the "compy" particularly menacing for humans, popular media have equally managed to transform it into a "miniature terror". In 1997, The Lost World: Jurassic Park made it a deceptively cute critter which attacks in huge packs and kills humans with a paralytic bite. While Compsognathus may have been cute (its name means "dainty-jaw"), in Real Life there is no indication of social behavior, and its thin jaws and peg-like teeth were strictly adapted to catch small prey. The fact that the original specimen's stomach cavity contained only a small lizard (namely, Bavarisaurus) would tend to support this.

  1. Entry Time: 1997
  2. Trope Maker: The Lost World: Jurassic Park (but already known by dino-fans long before that)

Brooding or robbing, lord or thief: Citipati, going by the name of Oviraptor *

Oviraptor lived in Late Cretaceous Asia 75 million years ago. This dinosaur is another demonstration about how Science Marches On is a crucial factor in popular dino potrayals.

First discovered in Mongolia in 1924 together with Protoceratops and Velociraptor, this toothless theropod was originally thought to be an ornithomimid. Since the 1970s it is classified into its own family, even more closely-related to birds. Oviraptor was distinct from ornithomimids by having a rounder, stockier beak, a shorter tail, and the small forth reversed toe on each foot present in most theropods (birds included), which was lost in ornithomimids. Unlike the latter, it was a "maniraptoran" theropod: its forelimbs were bird-like, and it's considered to have had a very bird-like covering of feathers, with feathered wings and a feathered tail fan.

It was given the name Oviraptor, meaning "egg-thief," because the first specimen (a crushed skull) was found next to a clutch of eggs which were thought to belong to the small ceratopsian Protoceratops. In the 1990s the eggs were found to contain oviraptor chicks: the specimen was brooding its eggs. This was further confirmed few years later, when an oviraptorid skeleton was found just above a nest full of the same kind of eggs. Before the middle 1990s scientists used to describe Oviraptors as a specialist nest-robbers, and documentary works have typically shown them frequenting the nesting ground of herbivorous dinosaurs (especially those of Protoceratops), grasping the eggs with their prehensile hands, and fleeing away from the angry mothers when they're discovered. As said above, the "robbing" behavior has often been attributed in popular culture to ornithomimids as well, but Oviraptor was considered specifically adapted just to eat eggs and no other kind of food, with its robust bill that was thought a specialization for breaking eggshells. Today, the actual diet of oviraptorids is a matter of speculation — they might have been fruit-eaters, predators, or both; they might even have fed on eggs if given the chance.

Since the first discovery the oviraptor has also notably changed its look: paleo-artistic works from before the 1990s usually depicted it featherless (like every other non-bird theropod), and with a protruding palate with a pair of teeth at the tip, believed apt to break eggshells. In works made in the Eighties you can see the animal with two different head-shapes: the one with a small bony bump on its nose (the more classical original one, but inaccurate), and the one with a square bony flat crest, first emerged in the 1970s (the most common image today in paleo-works, see also Prehistoric Life to go deeper within the argument). However, since the 2000s the most complete Oviraptor skeletons have been reclassified in a brand new genus, Citipati: the familiar square-crested image probably belongs to this new genus. Note that this is not the classic "Brontosaurus"/Apatosaurus case: the genus Oviraptor is still valid, it's just that many specimens that used to be considered to belong to the genus are now considered Citipati, and that the actual Oviraptor is very unlike its depictions, lacking any known crest and being far smaller that its emu-sized relative.

Unlike ornithomimids, oviraptorids have attracted the attention of dino-writers only since the 2000s: after the appearance of the feathered, non-egg-stealing scientific depiction. And yet, expect to see them portrayed in the older inaccurate way nonetheless, and you can also see oviraptorids and ornithomimids mixed up with each other. E.g. in the 2000 Disney movie Dinosaur, a featherless "Oviraptor" steals Aladar's egg, but loses it before it has a chance to eat the contents. More recently, an "Oviraptor" appeared in The Land Before Time TV series: feathered and not egg-stealing. Both portrayals show the oviraptors with a Citipati-like tall crest on their head. Dinotopia lampshades the animal's Science Marches On story showing it in two variations: the featherless "Oviraptor" and the feathered "Ovinutrix" ("egg-nurse").

  1. Entry Time: 2000
  2. Trope Maker: Disney's Dinosaur

The Big Brain: Troodon and the "Dinosauroid" *

This has been another complex case of Science Marches On as well, but also an astounding example about how imagination can be a very influential factor even for people studying dinosaurs seriously. Living in North America some 75-65 million years ago alongside giant tyrannosaurs, Troodon was a small dinosaur only around 7.9 ft/2.4 m in length and weighing some 110 lb/50 kg. It was still the largest member of the troodontid family, a sibling family to Dromaeosauridae and among the closest relatives to birds. Troodontids looked a lot like dromaeosaurids, including being covered with feathers. Specifically, Troodon was rather similar in shape to the Real Life Velociraptor; you can tell apart the two by observing the troodont's shorter head, smaller teeth, eyes pointing forwards note , shorter tail, longer legs, and less formidable sickle-claws on their second toe.

Since the 1980s Troodon has attracted scientists' attention because it shows several very specialized anatomical traits: it had larger eyes and ears than most dinosaurs, perhaps indicating nocturnal habits, and its brain was relatively large for a non-bird dinosaur as well. Its forwards-pointing eyes show binocular vision similar to modern birds of prey; many old portraits showed it with bulbous eyes with cat-like or even gecko-like pupils, almost resembling humanoid aliens (remember that last detail, we'll return to it at the end). More realistically, it had bird-like eyes with round pupils. It used also to be imagined with opposable thumbs making its hands like an eagle's foot to better grasp its prey, but this is controversial.

The troodont's actual diet is still debated: with its small, relatively blunt teeth, it was likely a mostly-carnivorous omnivore, though it used to be portrayed as a specialist small-prey hunter (mammals, dinosaur nestlings). Some recently have even hypothized it was an herbivore, but this is now mostly discarded. At the other extreme, some depictions attribute to it traditionally-dromaeosaurian traits such as pack behavior or the ability to kill large prey, which weren't possible in Real Life. Troodon 's toothed jaws and sickle-claws were too weak to tear the meat of large living animals.

The first find was a single tooth (hence the name Troodon, "wounding tooth"), one of the very first North American dinosaurs found (1856), but it was initially believed a lizard, then a pachycephalosaurian. Meanwhile, a small theropod, Stenonychosaurus, was described in the 1920s, and classified as a generic "coelurosaur". In 1987, Canadian paleontologist Phil Currie found the two animals to be one and the same, and Stenonychosaurus fell in disuse in favor of Troodon. If you read popular dino-books written before the 1990s, you'll probably find the name "Stenonychosaurus" more often. note  Also in the '80s, scientists found the troodont’s brain to be the biggest for its body size among all dinosaurs: this gave it the reputation of "the smartest dinosaur" in popular books note  — despite this, its brain was still smaller than most modern birds.

Despite an emergent tend to show up in documentaries, the troodont’s presence in fiction has been only occasional, and not related to the actual animal but to that could be called its "altmode". In 1982, when the time the animal was still called "Stenonychosaurus" and portrayed as featherless, Canadian paleontologist Dale Russell conjectured a possible way that descendants of Troodon could have evolved had it not gone extinct along with the rest of the dinosaurs. If its brain had kept increasing in size, today it would have been comparable to a human's. Combined with further evolution of its bipedal movement, binocular vision, and semi-manipulative hands, the resulting "Dinosauroid" was proposed to be a blend of featherless dinosaurian and humanoid features. The Dinosauroid has made a few appearances in novels and TV series; its Real Life dino-ancestor usually gets mentioned. It's worth noting that the Dinosauroid model resembles the Sleestaks of Land of the Lost (1974-1977), possibly a case of Ascended Fanon.

Recently, Troodon's validity has been called into question, as the type specimen only consists of teeth. While Troodon falls into taxonomic limbo, many fossils assigned to it have been moved into genera of their own, while Stenonychosaurus has been resurrected, much as Brontosaurus was.

  1. Entry Time: Uncertain
  2. Trope Maker: the "Dinosauroid" hypothesis in the 80s.

Cannibal or ancient Hero? Coelophysis *

One of the first true dinosaurs to appear on Earth, Coelophysis lived in Late Triassic North America 216-203 million years ago, although fragmentary material suggests a near worldwide distribution lasting up to 188 mya. Described during the Bone Wars from some pieces of bone, today it is by far the most abundant early theropod in the fossil record. In the 1940s, a whole graveyard with hundreds of specimens was found in New Mexico; they're widely theorized to have died all together in a flood, though this is not certain.

Coelophysis was a slim, fast-running dinosaur growing up to 10 ft/3 m, and weighing about 30 kg. Coelophysis looks like a fragile animal, with a narrow head, weak jaws with small pointed teeth, a long, stork-like neck (sometimes incorrectly described as "snake-like"), and an elongated, thin body. As an early theropod, Coelophysis was not very closely related to birds. For example, it had still a remnant of the fourth digit on each hand, and the presence of feathers is uncertain. It it had them, they were surely "proto-feathers" or down-like structures, not modern-looking feathers. note  Still, it had bird-like features showing how far back in time the dinosaur-bird link goes. Its skull and hindlegs were similar to the more evolved theropods; its bones were hollow and had airsacs within them (its name just means "hollow frame"); and it even had a tiny wishbone, a typically avian trait.

Coelophysis probably hunted down small prey, which it swallowed whole: lizards, dinosaur nestlings, fish, insects, proto-mammals, and whatnot. In the Triassic the top predator role was played by non-dinosaurian archosaurs like Postosuchus or Rutiodon, or larger theropods like Gojirasaurus. Coelophysis is often described as a "successful underdog" which finally managed to outcompete non-dino archosaurs, anticipating the following domination of the dinosaurs in the Jurassic world. It is usually portrayed as a gregarious animal that lived and sometimes hunted in packs; although pack behavior is possible, pack-hunting is unlikely.

In many works it's said adult Coelophysises ate younger members of their own kind (or even their own young) during famines. This because bones found in the stomachs of adult specimens from the aforementioned "graveyard" in New Mexico were reported to belong to young Coelophysis, leading to the dinosaur being described as cannibalistic. Later studies have determined that the bones in question were animals of other species. This doesn't mean that Coelophysis didn't occasionally eat their own kind (crocodiles and eagle-nestlings do this after all); only that there isn't any fossil proof anymore.

Together with the large herbivorous Plateosaurus, Coelophysis is the dinosaur you're most likely to see in those documentary works portraying the Triassic Period, to show how the earliest dinosaurs looked (even though in Real Life there were many other dinos in the Triassic, some even more primitive: Staurikosaurus and Thecodontosaurus are two examples). In these works, the smaller Coelophysis is used to represent the very start of the dinosaur evolution, while the bigger Plateosaurus represents a more advanced/enlarged stage. An excellent example of all this is the first episode of the TV documentary Walking with Dinosaurs, in which the two animals are shown living together in North America (in Real Life only the coelophysis was North American, the plateosaur was found in Europe).

On the other hand, Coelophysis has been far less common in fiction or other more popular media, since it is too humble-looking and generic to be interesting; the best-known appearance may be "Spot" from the 1974 children's television series Land of the Lost.

  1. Entry Time: 1974
  2. Trope Maker: Land of the Lost

A sickle-foot from Utah: Utahraptor *

As said above in the main dromaeosaurid section, Utahraptor was first discovered in Utah at the same time that the name Velociraptor became popular thanks to Jurassic Park. This animal was even larger and slightly older than Deinonychus, living 128-105 mya and being 23 ft/7 m long and as tall as a human. Its naming in year 1993 began an awesome case of science culture Ascended Fanon — before Jurassic Park, no genus of dromaeosaurids except Velociraptor had the -raptor suffix to its name. Since the film, paleontologists started to use it for naming most new dromaeosaurids.

Despite the scantiness of its original remain, the discovery of Utahraptor was much reported in media as it incidentally matched the size of the oversized JP raptors, or rather, was even longer than they were. Many then reported the Utahraptor as "the most fearsome killing-machines of all times", capable of killing, in packs, the biggest sauropods and even of destroying entire dinosaur species. However, Walking with Dinosaurs was not so extreme, showing Utahraptor hunting the relatively smaller Iguanodon — not in Utah but in Europe for some reason. Utahraptor, however, has proven to be quite the oddball for a dromaeosaur since it's rise to stardom, with new remains revealing it to have had stumpy arms, a short tail, short, robust legs and a unique dentition, similar to animals like Masiakasaurus. What exactly this bizarre new look entails for the behavior and ecology of Utahraptor, as of now, remains uncertain.

  1. Entry Time: middle 1990s
  2. Trope Maker: Raptor Red (novel)

The original Raptor: Dromaeosaurus *

How can we really tell Deinonychus apart from Velociraptor?

Other than their different size, this can simply be done by observing their skull. The Deinonychus head was relatively stocky, with a convex profile and the snout ending with a thin point; the Velociraptor head was narrower and more elongated, with a concave profile and a blunt snout. If you watch carefully the head of the Jurassic Park "raptors", you'll note it's modeled upon the robust skull of Deinonychus. This would demonstrate the latter is the actual animal people think when they think "Velociraptor". However, the JP Deinonychuses have also exagerrately fleshy lips and too large eyes compared with the more realistic portraits of the Deinonychus in dino-books; these two modifications actually make their heads looking like a cross between a Deinonychus and a Velociraptor. note 

After the Power Trio above, the most depicted "raptor" in media has traditionally been the namesake Dromaeosaurus albertensis ("Alberta's running lizard"). The eponymy is not a mere case however: this was indeed the very first discovered dromaeosaurid (1920s, in Alberta) and the generic meaning of "running lizard" is because its sickle claws were missing in its original skeleton, and scientists initially believed it was a small tyrannosaur or a more generic small theropod. The image of a hook-footed dinosaur came to light only after the description of Deinonychus in the sixties, and the family Dromaeosauridae itself was created around the same time to include Deinonychus, Dromaeosaurus, and Velociraptor together.

Dromaeosaurus was the same size of real-life Velociraptor but with a shorter head without the concave profile, and stronger jaws and teeth; compared with Deinonychus, Dromaeosaurus head was smaller but with a wider snout (good comparisons with Utahraptor cannot be made because of the incompleteness of the latter's skull). In spite of being less-frequently portrayed than them, Dromaeosaurus appears regularly in dino-books and has also made some apparitions in TV documentaries. If you see a dromaeosaurid interacting with Tyrannosaurus rex or Triceratops in Late Cretaceous North America, it would be Dromaeosaurus note  — unless the writers didn't know or just didn't care: some docus have shown Deinonychus or Velociraptor or even Utahraptor in this role. Walking with Dinosaurs dealed with the problem in a bizarre way: here, the dromaeosaurids are officially Dromaeosaurus… but have the shape of Deinonychus.

Actually, every dromaeosaurid in the original Walking With series was a Deinonychus, Utahraptor included note . And to make the "Utahraptors" and the "Dromaeosauruses" distinguishable, they show up simply with a different coloration: brownish the former, blackish the latter. In this show, "Utahraptor"s are also portrayed in the way dromaeosaurids were once represented in paleo-art: naked-skinned, colored rather like big cats, chasing an iguanodont in packs, jumping on it using their sickle-claws as spurs, and eventually killing it with (a quite exaggerated) ease. Many dino-books have made this thing Up to Eleven with Dromaeosaurus, depicting scenes in which these turkey-sized predators chase and kill in packs adult Edmontosaurus and Triceratops 500 times heavier! Current paleontology suggests that Dromaeosaurus and the other “raptors” hunted smaller (but still large) prey and only ate the carcasses of the giant herbivores.

  1. Entry Time: 1999
  2. Trope Maker: Walking with Dinosaurs

The four-winged critter that linked Dinosaurs with Birds: Microraptor *

Here's one of the latest entries in the Stock Dinosaurs realm.

Discovered in year 2000, Microraptor is one of the "Liaoning coelurosaurs" (see Prehistoric Life - Birdlike Theropods), named “small thief”; as the "-raptor" suffix suggests, it was a dromaeosaurid. It was a find that surprised not only casual paleo-fans but also the entire paleontology community. And not because it was a feathered dino fossil (such animals were already known from the same site), nor just because it was the smallest non-avian dinosaur known at that point (merely 1.5ft long, but this record is contended now by other non-avian maniraptors and some primitive ornithischians). It was its unique body-plan that astonished us all: a four-winged dinosaur!

More precisely, its hindlimbs had a feather covering incredibly similar to that of its forelimbs, giving it its unbelievable appearance. These wings had the same structure as the wings of true birds, with asymmetrical, vane-like feathers on the forelimbs, likewise on the hindlimbs, and placed in a "fan" at the tip of its long tail: in short, very similar to the kind of plumage of the well-known Archaeopteryx (itself recently found to have had remnants of such large feathers on its legs).

Of course, paleontologists and dino-fans have begun Wild Mass Guessing about its way of life. Since its discovery, Microraptor has been suggested to have been a tree-climber, with forelimbs as developed as the hindlimbs, both fitted with robust claws apt for climbing upright tree trunks; however, a study published in 2011 suggests it might have been terrestrial instead. The way it traversed the air is also controversial; with true flight like modern birds, or just simple gliding like modern “flying” squirrels, “flying” fish and “flying” lizards? Currently many scientists think Microraptor was actually a flier (although not as good as modern birds): not only that, it seemed to be even better adapted for flight than Archaeopteryx. If this is true, it would mean that flight evolved before the appearance of the so-called “first bird”, because Microraptor was less close to modern birds than Archaeopteryx was. And since flight was achieved in basal dromaeosaurids, this would mean that... yes, Velociraptor and all other dromaeosaurids may have descended from flying ancestors! One scientist did go Up to Eleven declaring that all maniraptorans descended from flying ancestors: this would mean, Troodon, Oviraptor, and even the huge Therizinosaurus were ancestrally creatures of the air, which, like ostriches or rheas, returned to a more ground-level way of life and increased their size. But all this is highly improbable.

Whatever the case was in Real Life, Microraptor immediately became the center of much interest soon after the year 2000, rapidly becoming popular in illustrated books (also because it was the considered the smallest dinosaur at the time); it became even more widely-known after being included as one of the main animal characters in the aforementioned Prehistoric Park (where it was portrayed with the classic, splayed-limbs gliding style, now known to be anatomically impossible). Soon afterwards, it started to gain attention in the broader pop culture world, and it has to at this point be qualified as a true Stock Dinosaur (even if only in the Rarely-Seen section, with one asterisk on the top).

  1. Entry Time: 2006
  2. Trope Maker: Prehistoric Park

A huge Dinosaur Mystery resolved, at last!: Deinocheirus *

Most bird-like dinosaurs were small and unimpressive in Real Life compared to most other dinosaurs. This definitively couldn’t be said for the following examples: Deinocheirus, Therizinosaurus, and Gigantoraptor, all living in Late Cretaceous Mongolia. These are indeed among the largest known theropods, and, and the same time, are (or have traditionally been) among the most mysterious.

Let's start with Deinocheirus mirificus (“astounding terrible hands”, not to be confused with Deinonychus antirrhopus, “counterbalanced terrible claw”). It was discovered in the 1970s in the Gobi Desert during an unusually rainy day for such an arid location, by the same Polish expedition that found the Protoceratops/Velociraptor fossilized battle and many other dinosaurs. Only its complete forelimbs were found by the scientists, along with shoulder-blades and some other fragments from the rest of the skeleton. The leading scientist of the expedition, Halska Osmolska, noted that these forelimbs were similar in shape to those of an ornithomimid… only, they were twice the height of a fully grown human. To give you an idea of the scale, several drawings have then shown these immense “arms” encircling an adult man, with the three-fingered hands (each as wide as a TV-set) shown like they’re going to grasp and then lift him.

The drawings usually don’t show the whole body, because its shape was totally unknown. After the discovery, a veritable Wild Mass Guessing started to understand what sort of thing Deinocheirus looked in life. Just as an example, some thought it had forelimbs longer than the hindlimbs: but this wasn't so, since this would have forced the animal to walk on four legs — an impossibility, since its hands were inapt for walking. We now know Deinocheirus had the same bipedal body shape of the classic ornithomimids.

Speculations about its size abunded as well. If its forelimbs had the same proportions of a Gallimimus, then Deinocheirus could have been bigger than a T.rex, and as long as a Spinosaurus — and even taller, thanks to the longer neck. It was even said that it could reach the fifth story of a building if alive today, and could have weighed as much as two elephants, that is to say, two T. rexes. But most experts didn’t agree with these extreme ideas, and put Deinocheirus in the same size-range as Tyrannosaurus or Allosaurus. Moreover, being an ornithomimosaur, it was imagined rather slender-framed, and thus unlikely that was as heavy as two elephants: perhaps even lighter than T.rex.

And then, there has been all the speculation about its way-of-life. Early reports described it as a gigantic and fearsome predator, but such an image was usually believed highly unlikely. Scientists didn't know if Deinocheirus was a basal toothed ornithomimosaur or a derived toothless ornithomimid, but if the first was true, it could have been an active hunter, and someone could have even imagined titanic battles againts the contemporaneous T. rex relative Tarbosaurus or even Therizinosaurus. But even with sharp-toothed jaws, Deinocheirus shouldn’t be seen as such a powerful killer. Its jaws and teeth would be much smaller and weaker than tyrannosaurs', carnosaurs', or even spinosaurids'. Furthermore, its claws are too blunt to be able to rip the tough skin of a hadrosaur or a sauropod. The main consensus was Deinocheirus was a sort of giant omnivore, which could have eaten from tree-tops using its forelimbs to pull down branches, and at the same time could have scavenged carrion of large herbivores, destroyed termite-mounds, hunted small dinosaurs that could be swallowed whole, and maybe chased Tarbosaurus away from their kills using its “terrible hands” as a scaring device.

To resolve the mystery, dino-fans patiently waited for a complete Deinocheirus skeleton for many, many years. Material described in 2012 was a step in the right direction: this shows that the original carcass was scavenged by Tarbosaurus. But in the 2013, after 40 years of waiting or so, the so-much attended answers arrived at last. Two almost-complete specimens of Deinocheirus were found near the original one (they weren't found by the Polish scientists by misfortune). This new material confirmed and debunked all the hyps above: Deinocheirus was really an ornithomimosaur, but displays a feature unknown in any other birdlike theropod: a sail that peaks over the hips, similar to that of the carnosaur Concavenator. In 2014, its skull was found, which resembled that of the duckbilled hadrosaurs but with no teeth. In the same year, new evidence emerged revealing that Deinocheirus had a thicker lower jaw than previously thought and fish remains were discovered in one specimen's stomach. This suggests that Deinocheirus was an omnivore that mostly fed on ground level and aquatic vegetation and also ate small animals when it could.

Deinocheirus, in addition, became the largest dinosaur with evidence of feathers, as its tail showed pygostyles where feathers were attached, proving size did not rule out feathers — after all, modern elephants rhinos & hippos do have hair just like every other land mammal. Also it was revealed that Beishanlong and Garudimimus were the closest relatives of Deinocheirus, forming the family Deinocheridae (whose Deinocheirus was originally believed the only member), thus putting the latter very close to true ornithomimids in the evolutionary tree. Described as recently as in October 2014, the two new specimen were slightly bigger than the original one, and indicate that Deinocheirus actually was one of the biggest and tallest theropods ever: about 6-7 tons (like a big T.rex), more robust than typical ornithomimosaurians, and one of the biggest animals of its fauna (the weight of a small titanosaurian sauropod), thus outweighing and outmighting its potential predator Tarbosaurus. In short, Deinocheirus instantly went from being one of the biggest paleontological mysteries of the twentieth century to an animal whose appearance and lifestyle are well understood.

  1. Entry Time: 1980s
  2. Trope Maker: The portrayal of its forelimbs in popular dino-illustrations

Wolverine-Claws or Colossal Freak?: Therizinosaurus *

Many dino-fans have qualified this guy and other similar giant birdlike theropods as "colossal freaks" because of the mystery surrounding them.

Therizinosaurus could be considered the Non Identical Twin of Deinocheirus above. It was colossal yet awfully bird-like, just like Deinocheirus; specialized to a non-big-prey-based diet, just like Deinocheirus; was discovered in Late Cretaceous rocks from Mongolia, just like Deinocheirus; is known mainly from forelimbs and few other bits, just like Deinocheirus before 2014; entered the dinosaur list around the same time as Deinocheirus; and, last but not least, it is another candidate for the title of biggest theropod, just like Deinocheirus! But, unlike Deinocheirus, Therizinosaurus was not a giant ornithomimosaur, but the biggest member of the Segnosaurians (today called Therizinosaurians).

Discovered in the 1950s but not recognized as a dinosaur until the 1970s, its forelimbs were slightly shorter but more powerful than those of the giant ornithomimosaur. But Therizinosaurus had an additional curiosity: three scythe-like claws on each hand (hence its name, "scythe lizard"), some as long as a human arm. In short, it had the biggest nails known so far within the entire Animal Kingdom. One of these oversized claws was in fact the first known find, and for several years, scientists thought it belonged to a giant marine turtle! Indeed, its fully scientific name, Therizinosaurus cheloniformis, means "turtle-shaped scythe lizard".

With such powerful weapons, Therizinosaurus has in the past received the same treatment as Deinocheirus. Some old drawings went as far as to show our "scythe-dino" as a giant carnosaur or deinonychosaur with sickle-claws on each foot (if Therizinosaurus was really shaped that way, it would really have been the most badass dinosaur one can imagine...). More accurate analyses made at the beginning of the 1990s definitively debunked these fantasies: we now know with a good level of certainty that Therizinosaurus was a bulky-bodied, round-bellied, and quite slow-moving animal that used its claws mainly to pull down branches. Furthermore, its jaws were arguably weak with a rounded horny tip and small grinding teeth similar to those seen in its smaller but better-known relative Segnosaurus.

This obviously doesn't lessen its general coolness: even with this new shape, Therizinosaurus remains an odd-looking, powerful beast, and thanks its massive body, it might even be the biggest and heaviest theropod ever discovered, weighing even more than the famous Spinosaurus.

As we've long done with Deinocheirus, we dino-fans are patiently waiting for exciting new remains of our "Wolverine Claws-osaurus" to be excavated. Meanwhile, Chased By Dinosaurs from 2002 temporarily recreated our imagination in CGI: in the episode titled "The Giant Claw" Nigel Marven talks about Therizinosaurus, lampshading its whole Science Marches On story from a mighty carnivore to a Gentle Giant. Nigel is in Late Cretaceous Mongolia searching for the possessor of the eponymous "giant claw", which the zoologist believes to have pertained to a fearsome predator. After several adventures with other famous dinosaurs of the habitat (Saurolophus, Protoceratops, Velociraptor), Nigel witnesses a fight between Therizinosaurus and Tarbosaurus: even though the former unexpectedly reveals itself to be an herbivore, it easily defeats the tyrannosaur by slapping it in the face with its scythe-claws, obliging the predator to flee. Finally, the therizinosaur licks Nigel’s face. Really!

  1. Entry Time: 2002
  2. Trope Maker: Chased by Dinosaurs

Gigant(ic) O(vi)raptor: Gigantoraptor *

Most Oviraptor relatives were small-sized like their group's namesake, except one: Gigantoraptor erlianensis. Discovered in Asia only in 2007, this dinosaur, despite its name ("gigantic thief"), is not an overgrown dromaeosaur, but an overgrown oviraptorosaur.

Gigantoraptor was 25ft in length, and the only known skeleton was only a "teenager"; an adult would have been bigger, almost as big as the neighboring tyrannosaur Tarbosaurus, but with the anatomy of the classic oviraptorosaurs. If the oviraptorosaurian way of life has been hard to decipher (consensus seems to have them being originally herbivores, but re-evolving into pure carnivores), imagine what kind of headscratching Gigantoraptor caused. It's all cool, though: three, generally small-sized lineages of non-avian coelurosaurs have a few oversized members within their ranks: Deinocheirus the giant ornithomimosaur, Utahraptor the giant dromaeosaur, and Gigantoraptor the giant oviraptorosaur. On the other hand, tyrannosaurs and therizinosaurs include many gigantic species, while other coelurosaurs, such as the troodonts, have none. But who knows? Maybe one day a “Gigantroodon” would be discovered…

Together Deinocheirus, therizinosaurids & Gigantoraptor make a strange case: such overgrown birdlike theropods seem an almost only-Asian affair, and nobody knows why similar animals have never been found in North America note  — considering the strong similarity of the two faunas in the Late Cretaceous, which should even communicate to each other through the Bering landbridge. Maybe could the competiton with the almost-exclusively American Ceratopsids have prevented North-american maniraptoriformes to reach larger size? note 

Like Therizinosaurus, only parts of the skeleton of the gigantoraptor is known. While Deinocheirus was an omnivore, and Therizinosaurus was a herbivore, Gigantoraptor has still no consensus regarding its diet. Its close relatives show predatory adaptations and are known to have eaten small prey like lizards, and this is the most likely option so far, but considering that it's another giant "freak" nobody can be sure.

Despite being a very recent find, Gigantoraptor soon recevied some mild media attention, appearing in paleo-documentaries like Planet Dinosaur and Dinosaur Revolution. The awesomely-named Gigantoraptor could be considered as a true Stock dinosaur at this point.

  1. Entry Time: 2010s
  2. Trope Maker: Recent paleo-documentaries

Bird-Thief or Jurassic Coyote?: Ornitholestes *

Ornitholestes (not to be confused with the similarly-named Ornithomimus) was a slender animal the same length/size of the Real Life Velociraptor (2 m long) but with a rather incospicuous appearance, that lived alongside Allosaurus, Stegosaurus, Apatosaurus, and fellow small theropod Coelurus in Late Jurassic North America, 150 mya. Within their habitat, Ornitholestes and Coelurus arguably played the role of the “small cunning predators” (while Allosaurus and Torvosaurus were the top predators and Ceratosaurus was between the two extremes). Although there are no evidences, their preys were possibly lizards, mammals, frogs and insects, and sometimes, also ate the eggs and hatchlings of bigger dinosaurs. In the “Time of the Titans” episode of Walking with Dinosaurs we can see some Ornitholestes behaving in such a way. In many paleo-artistic works Ornitholestes has been shown behaving like a jackal, tearing chunks of flesh from the kills of Allosaurus or Ceratosaurus and fleeing safely from these larger predators.

Ornitholestes was found a bit later than Coelurus, at the beginning of the 20th century. Its name, “bird thief”, was given because it was though a specialist predator well-adapted to grasp “first bird” Archaeopteryx with its prehensile hands. Such a thing would not technically be impossible, the two being contemporaries… only, the “proto-bird” lived in Europe. In many modern portraits, Ornitholestes used to be shown with a horn-like crest on its nose, seen even in Walking with Dinosaurs; however, we know now that it didn’t have this feature. Walking With also added some speculative erectile quills on its neck: though not demonstrated, these might be possible, especially as Ornitholestes has recently been classified as a bird-like maniraptoran in some analyses (albeit still of uncertain placement within the clade: maybe a distant relatives of dromaeosaurids and troodontids). The link with maniraptors is further reinforced by one detail: Ornitholestes had a retractable toe similar to that of deinonychosaurs and early birds, even though almost-every pictures (WWD included) show it with generic bird-like three-toed feet.

  1. Entry Time: 1999
  2. Trope Maker: Walking With Dinosaurs (the Time of the Titans episode)

An even more ancient Hero: Herrerasaurus *

Thanks to dino-books and documentaries like those of the Walking with Dinosaurs series, several people have become conscious about the existence of Coelophysis, which has become “the forerunner of the dinosaur world”. However, some carnivorous dinosaurs lived even before it; but are so ancient, that could not even be real theropods.

In Triassic world, dinosaurs still were not so differentiated each other, and the familiar “Coelophysis” shape was shared by several other animals, obviously with some degree of variation. Herrerasaurus, Staurikosaurus and Eoraptor are the three most classic examples. Together, the first two form their own dinosaur subgroup, the Herrerasaurians, whose namesake Herrerasaurus is the official prototype.

Its shape was typically theropodian, but its skeleton was more archaic and less bird-like; for example, it had five digits in its feet, more similarly to sauropodomorphs like Apatosaurus or Plateosaurus than to neotheropods — the technical name for theropods more evolved than herrerasaurians, when the latter are considered true theropods — which have only four. Also its pelvis was unique. This bony-puzzle was responsable of many headaches among paleotaxonomists: Herrerasaurus, indeed, has been variably classified as true theropod, true sauropod-relative, a generic primitive saurischian, and in the most extreme case, even a non-dinosaur at all!

Herrerasaurus was discovered in the 1960s in what is now Argentina, It was a bit longer than a Coelophysis (3-4 m) but much more robust, with a larger, stronger head and shorter neck, almost-recalling more a miniature "carnosaur" than a "coelurosaur" (in the former senses of these words). Herrerasaurus was arguably a more powerful predator, hunting relatively larger animals than those of the coelophysis, such as the beaked rhynchosaurs, mammal-ancestors, and small-sized dinosaurs like Pisanosaurus — but retreated against the giant prosauropod Riojasaurus (even bigger than Plateosaurus) or the 7 m-long carnivorous dinosaur-relative Saurosuchus.

Some Herrerasaurus remains were put in their own genuses, "Frenguellisaurus" and "Ischisaurus". Herrerasaurus was found in Ischigualasto, the formation in Argentina in which it and other dinosaurs & non-dinosaurs have been found — the complete name of this dinosaur is indeed Herrerasaurus ischigualastensis.

  1. Entry Time: undetermined
  2. Trope Maker: Popular dinosaur books

Other small or birdlike theropods

Sorry, these ones aren't here. If you're looking for Bambiraptor, Coelurus, Alvarezsaurus, Scipionyx, and others, see here. And here. And also here.

    True birds 
As easy as it is to forget, birds are dinosaurs as well. Specifically, birds are members of the maniraptoran clade, which also includes the aforementioned dromaeosaurs, troodontids and oviraptorosaurs. Yes, that means that dinosaurs are technically not extinct! These contain the only Cenozoic dinosaurs on this list.

Symbol of Man's Folly: The Dodo ***

Perhaps the most recently extinct stock dinosaur (in a technical sense, anyway), having been wiped out before 1700 in full Modern Age, the dodo (scientific name: Raphus cucullatus) was a turkey-sized flightless pigeon that lived on the isolated island of Mauritius. The pigeons it was descended from almost certainly flew to the island, but because there were no land predators, the dodo evolved secondary flightlessness, no longer needing the luxury of flight—which may have been an evolutionary mistake, considering what happened when humans and their pets showed up. Its diet likely comprised of fruit and seeds, as well as possibly insects.

The circumstances of the dodo's extinction are commonly misinterpreted. The most common explanation was that they were simply unable to comprehend that humans were NOT friendly and thus were hunted for their meat until they all died out. In reality, while it is likely that these birds were a little too brave for their own good (many modern birds on Mauritius still can't take the hint), they certainly weren't helpless creatures—their beaks were very large and sharp and reportedly were capable of delivering painful nips if the dodos got agitated. Additionally, the meat of the dodo was said to have been very tough and oily, making it very unpalatable for human consumption. It is now thought that the demise of the dodo came along because of the invasive species brought into the island—rats and cats ate the babies and eggs while pigs and dogs ate the adults. In addition to the previously mentioned flightlessness and possible Fearless Fool status, dodos were very slow breeders who couldn't repopulate faster than invasive predators were eating their young, so it wasn't long before they all disappeared.

Dodos are frequently thought of as having been stupid creatures, to the point that we have a trope for this portrayal and a proposed origin for its name was a Dutch word meaning "simpleton". We now know that dodos were no more or less intelligent than any other pigeon and that because it was a pigeon, a more likely origin for its name was the sound it made, which most likely sounded like a soft "doo-doo". The dodo had a cousin on a neighboring island called the Rodrigues solitaire—which sadly also went extinct—and its closest living relative is the Nicobar pigeon. Other extinct birds from the Mascarene islands (Mauritius, Reunion, Rodrigues etc.) included a giant ground-dwelling parrot, a harrier, a sparrowhawk-like owl, a sundry assortment of flightless rails, and even a flightless ibis (the latest one was once believed a dodo relative, the "Reunion solitaire").

The dodo is probably the most famous extinct animal that didn't come from the Mesozoic or the Pleistocene Ice Age, to the point that a notable euphemism for death or obsolescence is "going the way of the dodo" or "dead as a dodo". On a more serious note, the dodo's extinction is one of the things that has motivated humankind to try and be more environmentally minded—after all, we were able to drive this innocent, goofy-looking bird to extinction, who's to say we won't end up wiping out more species? Sadly, not everyone got the hint, not to mention we lost many species before the dodo too, for example the giant running-birds Moa from New Zealand and Elephant-Bird from Madagascar (see below).

The dodo's fame probably started with Alice's Adventures in Wonderland, when an anthropomorphic dodo appears among the animals Alice encounters in Wonderland. The Dodo in the book is said to be an Author Avatar for Lewis Carroll. Dodos have appeared all over the media, usually depicted in the outdated, fat, stupid waddling birds portrayal, as opposed to the thinner and more bold birds that we know they were now. They'll often be put into a post-dinosaur world for comic relief—for example, in Ice Age where the dodos are depicted as possessing almost suicidal stupidity. Most media will also forget that the dodo is a pigeon. Regardless, the dodo will almost never be depicted as a Prehistoric Monster, unless it's mutated or something, and even then it will be seen as a joke rather than a threat, as was the case in Series/Primeval.

  1. Entry Time: 1865
  2. Trope Maker: Alice's Adventures in Wonderland

Dinosaurs continued to rule: Gastornis & Phorusrhacos **

Long-standing paleo-fans will remember the name "Diatryma" for sure: that large, flightless, large-headed predatory bird who used to hunt the small "horse" Eohippus in so many paleo-artistic depictions placed in Eocene North Americanote . Well, now poor "Diatryma" seems having definitively disappeared... but luckily, it hasn't, as such: it's simply changed identity. Now we have to call it Gastornis (a far less awesome name, we've got to admit, but... never mind). Whatever name should be used, this has always been one of the most enigmatic extinct birds.

Recently, it was shown that it wasn't probably even carnivorous at all: its strong beak wasn't hooked like an eagle's, and its body frame was stocky, seemingly slow-moving. It probably only was a mainly-herbivorous omnivore that used its bill to crack nuts and cut vegetation — making erroneous the Bizarro World portrayal in Walking with Dinosaurs where these birds were shown ruling mammals. However, this does not mean it was the Gentle Giant news articles claimed it was. Ostriches and cassowaries are mainly herbivores too, but they're also some of the few birds that have been known to kill people. And Gastornis not only grew to their size, but it also had a powerful beak that would've been useful for fighting off the land-dwelling crocodiles like Boverisuchus that were the true dominant predators. Anyway, the gastorn/diatryma was a literal and figurative giant in its forested world, 40 million years ago: while mammals were still mostly small (except for some pantodonts and mesonychians), some birds grew to large size.

With the Phorusrhacids, on the other hand, we did never have doubts this time: thanks to their light weight and slender running legs, they surely were active hunters of small mammals. And with their strongly hooked, very eagle-like bills, they probably did not always swallow their prey whole. They were once thought to have one clawed fingers protruding from each of their tiny wings, for uncertain purpose. This is not so strange as one may think: there are also living birds with this feature, the most notable being the two-fingered young Hoatzin. However, it was later discovered that their living relative (below) has similarly-shaped wings and lacks wing claws, making these fingers unlikely. Among the most amazing-looking among all prehistoric birds, phorusrhacids have recently been nicknamed terror birds in pop-documentaries (for example, Prehistoric Park).

Originally from South America, they have left a legacy in our modern world as well: the closely-related seriema is a medium-sized South American bird whose shape and habits resemble a miniaturized "terror bird", as well as the not-related African secretarybird which is actually an eagle-relative. The prototypical South American Phorusrhacos (often misspelled "Phororhacos" or "Phororhachos") lived in the Miocene, before hominids and true sabertoothed cats appeared, while the North American Titanis (lit. "the titanic one", which first originated in South America as well) lived in full Ice Age. They are the two most portrayed species of the family: among the others, Kelenken was found only recently in Argentina, in 2007, but is now the largest known phorusrhacid. It lived earlier than Titanis, about the same time of Phorusrhacos. Another less-known members were less-tall but more robustly-built than them, ex. Brontornis ("thunder bird").

Despite being only distant relatives, and the aforementioned Science Marches On, expect Gastornis to be lumped in or confused with the true "terror birds" anyway. In fact, Gastornis was actually more closely related to waterfowl than to the Phorusrhacids, which in turn were closer to birds-of-prey, parrots, and songbirds according to the most recent molecular research. Their most notable appearance in non-documentary fiction is in 10,000 BC, where they fill the role of raptors. Never mind that, even if species like Titanis walleri did live alongside early humans, they never made it to Egypt where the film appears to take place.

  1. Entry Time: start of the XX century
  2. Trope Maker: The paintings of Charles R. Knight (both "Diatryma" and phorusrhacid); Walking with Beasts popularized in year 2001 the diatryma's new name Gastornis

Giants of the South Islands: the Moa & the Elephant Bird *

Giant dinosaurs were not exclusively an only-prehistoric affair: two really large birds have lived in human historical times: the Moa and the Elephant Bird.

Both were Ratites, aka flightless birds related with ostriches, rheas, cassowaries, emus, and kiwis. Moas, also called Dinornithines from their best-known genus (Dinornis, "terrible bird") lived in New Zealand like the more popular icon of this country, the kiwi. The biggest moas, obviously, are the most shown in media, expecially Dinornis maximus (maximus = "the biggest"): others, though, were fairly smaller, like Emeus crassus (lit. "fat emu"). D. maximus reached 3.5m /12ft in height, much taller than the tallest living ostrich (9 ft at the most), and were also more heavily-built, with stocky legs and massive body: they could have weighed 250 kg or more (ostriches at the most weigh 150 kg).

According to semi-fossilizied remains, moas' plumage was rather similar to a kiwi's in texture and color, and like the latter they had no visible tail. They reduced their wings to an extreme, even more than the kiwi itself note : moas were totally devoid of them, even in their skeleton (except for the remnants of shoulder-girdle and humeri), making them one of the most extreme cases of reduction of the anterior limbs among theropods.

Moas were by far the biggest New Zealand animals of their time: they had small heads and bills, long giraffe-like necks, and were probably slower and more strictly herbivorous than modern running birds, which also eat insects or small invertebrates other than plant matter. They had no potential predators that could have killed them, except for two: Harpagornis, the "Haast's eagle" which preyed upon smaller species & the juveniles of the biggest ones, and more importantly, humans. The ancestors of the Maoris first colonized the distant New Zealand archipelago during the european Middle Ages, probably heavily hunted them, and/or gathered their eggs, or set fires, unwillingly eliminating the few still-living dinornithan species. Kiwis managed to survive, but then, European colonizers reached the islands introducing several household mammals in the wild, which almost managed to delete the animal they later chose as their national symbol.

On the other hand, the Elephant Birds or Aepyornithines (the latter name meaning "lofty bird": the two most portrayed species are, again, the biggest ones, Aepyornis maximus & Aepyornis titan) lived in Madagascar, the large african island whose most famous animals are the lemurs. They shared with moas a similar appearence, with similarly-reduced "wings"; but were even more massively-built, with huge body and very stocky "elephant-like" legs — hence the common name. The biggest elephant-birds were maybe the largest/heaviest birds of every time (but less-tall than giant moas), and possibly behave the same way of the latter,and probably were herbivorous as well.

During the first explorations of the Malagasy island made by European navigators after the XVII century, they found the fragments of some truly gigantic eggshells, belonging to eggs twice the diameter of the biggest modern eggs (those of the ostrich of course, that are about one foot of diameter), and still-today the biggest known eggs of every dinosaur/land animal known.note  Later, other semi-fossilized remains were found of these critters, the biggest of them revealed being among the heaviest birds ever, if the heaviest (maybe more than 540 kg): slightly less-tall than giant moas, but more stocky-builded and thus heavier than them as said above. Only the biggest dromornithines (another group of extinct flightless birds, this time from Australia) could have rivalled them in mass.

The extinction of the aepyornithines is still unclear: they hadn't natural predators when adults unlike the moas, and only humans could have drived them to their fate. There are different hypotheses about both the real cause of their demise (hunting? introduction of foreign species? egg gathering?) and even the precise period of their disapparition. Some have speculated, however, that the mythical Roc bird was inspired from ancient Arab sailors who saw these birds alive in the Middle Ages. This is controversial though, since the Roc, unlike the elephant-birds, used to be portrayed like a giant flying bird of prey.

  1. Entry Time: undetermined
  2. Trope Maker: Educational works

The Penguin of the North: the Great Auk *

Here's another recently-extinct bird that is rather common in popular paleo-sources. The Great Auk's scientific name is Pinguinus impennis ("featherless penguin", but was feathered!). This is not a mere coincidence however: indeed, the word "penguin" originally just indicated this bird, which people used to see in the Northern Atlantic coastlines before the spheniscids (aka the commonly-intended "penguins") were actually discovered in the XVI century, during the first explorations of the Southern Seas. In other words, Polar Bears and Penguins was once Truth in Television! However, the Great Auk' areal was a bit souther than the polar bear's, and the two, living in different habitats, could not have encountered each other in life.

The Great Auk was a relative of modern puffins, murres, and razorbills: that is, it was a member of the Alcids, the "Auk family", and was also related more distantly with seagulls, terns, woodcocks, plovers and so on (all of them belong to the bird-group named Charadriiformes). It resembled a modernly-intended penguin because of its erect pose, black & white plumage, and palmated feet, but mainly because it was flightless (unlike the other modern auks), with very reduced wings unapt to fly. It was pretty large, too: 3 feet tall and weighing several kilograms, much more than still-living auks, but still smaller than an Emperor Penguin (the biggest living spheniscid) or the toothed Hesperornis (see below).

Sadly, this large specialized seabird was depleted by us humans during the XIX century thanks to overhunting: the last two specimens were killed in year 1844, two centuries later than the equally-flightless tropical dodo. Indeed, all around the world, flightless birds have revealed to be the most vulnerable to extincion, expecially those living in insular worlds — see the gigantic moas in New Zealand and elephant birds in Madagascar, but also smaller birds like the Moa-Nalo ducks in the Hawaii, and the Takahe and Kakapo in New Zealand, both of which managed to escape the fate Just in Time.

Unlike other historically extinct animals like the iconic Dodo (Alice in Wonderland and more recent media) and the cattle-ancestor Aurochs (painting in caves and ancient literature), the Great Auk is mentioned mainly in modern scientific or educational works — often as an example of the Man's foolishness: like the dodo bird, it was said the auk was a kinda Fearless Fool toward its human hunters. Its flightlessness would make it appearing goofy/innocent like its tropical equivalent dodo, or even cuter than it because of its striking penguin-look.

  1. Entry Time: undetermined
  2. Trope Maker: Educational works

Toothy penguin and toothy seagull?: Hesperornis and Ichthyornis *

Hesperornis ("western bird") and Ichthyornis ("fish bird") have traditionally been the two most commonly depicted Mesozoic birds in books (not counting the superfamous "missing-link" Archaeopteryx of course), both from Late Cretaceous North America unlike the latter which was Late Jurassic and European. Both were discovered during the Bone Wars by Othniel Marsh. Since Hesperornis is far cooler, here we'll mention it first. Hesperornis (whose original species is called regalis, "royal" in Latin) lived in the same habitat in which pteranodonts, tylosaurs, elasmosaurs and archelons roamed: the shallow inland sea which used to cover the American Midwest at that time, dividing North America in two parallel strips of land running from the Arctic down to the south. Despite living in such an early period, Hesperornis was already a very derived bird. 6 ft long (the size of a human, taller than an an Emperor penguin and much taller than the recently-extinct Great Auk), it was flightless like them, with vestigial wings (like all the birds already listed above), short splayed legs for swimming, a long neck, and a long beak, but unlike them had small true teeth. It spent most of its life in water but returned on land to lay its eggs, again like a penguin and an auk. Once, indeed, the hesperornis was shown as a sort of proto-penguin, and with an erect pose; we know now its legs were too weak to support its body in the manner of spheniscids (the scientific name of true penguins), and the animal is now portrayed as more similar to modern grebes and loons. It was often depicted with the typical palmated feet like a loon or a swan, but it's more likely it had flattened toes like a grebe or a coot (a water rail). Similar to Hesperornis but smaller, Baptornis ("diving bird") also lived in the same shallow seas.

The much smaller Ichthyornis dispar lived in the same age and habitat of Hesperornis, but this time we're faced with a sorta toothed, long-billed proto-seagull. This is the first flying bird encountered here in the Useful Notes about stock true birds; flighless birds, either large or small, land- or water-dwelling, seem indeed to be the favorite extinct birds in media — probably because of their oddity of not-flying, but some spectacular flying birds did exist in the Mammal Age, like the "giant condor" Argentavis (below) and the "giant albatross" Pelagornis, both with the wingspan of a giant pterosaur like Pteranodon.

The ichthyorn's lifestyle was arguably similar to modern flying waterbirds, catching fishes in flight like modern terns, or maybe diving under the sea to pursue them like modern boobies. You can almost be certain that if pterosaurs are involved, these little guys will be depicted as pests who like to steal food from them (probably originated in year 2000 from the Disney's Dinosaur film): this behavior was possible, but has never been proven. In Real Life both ichthyos and hesperos sometimes fell prey to large marine reptiles, as shown by remains of stomach contents (ex those of mosasaurs). Despite their primitive, dinosaur-like toothed skull, the remaining skeleton of both Ichthyornis and Hesperornis was almost full birdy at this point note . If alive today, apart of their teeth they'll be easily taken for components of modern avifauna. In some artistic works, both Hesperornis and Ichthyornis are depicted as black and white like modern gulls or penguins, but their real coloration is totally unknown.

While these two do feature prominently in dinosaur books and sometimes documentaries (Hesperornis, for example, was the token prey animal in Sea Monsters and Ichthyornis got a bit part in Dinosaur Planet as a scummy scavenger), their presence is rare in more mainstream media, presumably because, besides their teeth and Hesperornis' large size, they don't have a lot of cool points (unlike the exotic Mix-and-Match Critter Archaeopteryx and the large "terror-birds") — even though other spectacular extinct birds like the Dromornithids, the Teratornithids, the Pelagornithids, and the giant true penguins (all from the Caenozoic) have had even less fortune despite their impressiveness. That hasn't stopped folks from trying to portray the two Mesozoic toothy birds, for better or worse. An Ichthyornis, creatively and perhaps fittingly named "Ichy" appears as a one-shot villain in the fourth Land Before Time movie, accompanied by an equally villainous crocodilian Deinosuchus. Ichthyornis also cameos in Dinosaur, erroneously depicted as duck-like creatures rather than seagull-like, and are among the many factors contributing to the start of the movie when they attack the mother Pteranodon carrying Aladar's egg, causing her to drop it. In Primeval, Hesperornis appears as an aggressive but non-malicious creature that kills a plumber after its anomaly appears in someone's flooded basement. It's portrayal there is probably one of the worst of any prehistoric bird — to the point that the creature designers had it featherless (every real ancient or modern bird has feathers, even the apparently-featherless penguins) and standing upright like in the ancient classic illustrations.

  1. Entry Time: early 2000s
  2. Trope Maker: Disney's Dinosaur (Ichthyornis); Primeval (Hesperornis)

Feathered airplanes: Argentavis and Osteodontornis *

Argentavis magnificens (lit. "magnificent argentinian bird") is probably the most famous flying bird among those living after the dinosaurs.

Along with giant pterosaurs and the ancient "dragonflies" like Meganeura and Meganeuropsis, Argentavis and the unrelated Osteodontornis orri (and the less-known relatives of both) deserve the Giant Flyer title more than every other prehistoric creature. Both had a wingspan of about 7 m, as much as Pteranodon; and Argentavis weighed an impressive 80 kg (like a small ostrich). To understand how majestic these two ancient birds were in life, imagine Argentavis as a giant condor with a ostrich-sized body, huge roc-like wings, a sharp uncinated beak, and a love for carrion (and maybe even an occasional hunting attitude). While Osteodontornis (lit. "bony-toothed bird") was a marine bird rather looking like a giant pelican or albatross, but with a serrated beak.

Found in 1980 in Argentina at the start of The '80s, Argentavis lived slightly before the famous "American Pliocenic Interchange" of fauna from the two Americas, and was nearly contemporaneous of the giant running bird Phorusrhacos. It was even quite similar to the latter, but the argentavis was much shorter-legged, shorter-necked, and enormously more bigger-winged; both, incidentally, shared the typical eagle-like uncinated beak for tearing meat, but were not close relatives. While the phorusrhacid was basically a sorta giant flightless secretarybird (and often portrayed with the latter's plumage), Argentavis was more like a giant vulture, but belonged to a distinct family from modern condors: the Teratornithids, and sometimes nicknamed "the giant teratorn" for this. Since its discovery, it has often cited in popular paleo-books as "the largest flying bird ever discovered", but very recently the osteodontornis' relative Pelagornis sandersi has revealed to be possibly even larger.

Despite their impressiveness, the "Argentinian Bird" and the "Toothed Albatross" have yet to appear in fiction (incidentally, like the former's almost-namesake giant sauropod Argentinosaurus, the "Argentinian Lizard"). But the strangest thing is another: the coolest of the two, Argentavis, has actually had one single apparition in documentaries to date: "Paleoworld", as a side-note of Phorusrhacids! Since the Walking with Beasts producers did recreate Argentavis world (in the Sabretooth episode), they wasted a perfectly good opportunity. This doesn't mean, however, that Argentavis magnificens and Osteodontornis orri could not obtain more consideration in the future.

  1. Entry Time: uncertain
  2. Trope Maker: documentary media

Other birds

Sorry, these aren't here. If you're looking for Aurornis, Confuciusornis, Enantiornithines, Dromornis, Presbyornis, Teratornis, Ornimegalonyx, and others, see here.

Long-necked plant-eaters

The sauropodomorphs ("sauropod-shaped") include dinosaurs with long necks. Most of them pertain to the sauropod subgroup, while all the other members are traditionally called prosauropods.


Sauropods are the (mostly) gigantic quadrupedal plant-eating dinosaurs with long necks and tails. Some of them were the largest land animals that ever lived, but not quite as massive as they seem: the weight of most of them was brought down significantly by a system of air sacs in hollow bones, similar to theropod (and hence, bird) skeletons.

Since sauropods are rather similar to each other in size and appearance, only a few of them will usually be identified/identifiable in Fictionland: Brontosaurus, Brachiosaurus, and Diplodocus. Their iconic status is due to several factors: the early time of their discovery, the relative completeness of their remains, and for having held some "record" in the past — Diplodocus has long been the "longest" land animal ever, the brachiosaur the "tallest" and "heaviest", while Brontosaurus, being the very first mounted sauropod in a museum, was the first that became popular. Today scientists recognize more than two hundred sauropod genera, but pop culture ignores most of them. All the three most known sauropods are from Late Jurassic North America (even though the best-known brachiosaur species was found in Africa), but in Real Life sauropods lived worldwide from the Early Jurassic up to the end of the Dinosaur Age. However, in recent years some other sauropods have received attention in media, but only because were said to be "Longer! Taller! Heavier!" than the traditional record-holders. Some really were, but other weren't even real animals. You can find them here classified as "little stock". Camarasaurus, Mamenchisaurus, and Saltasaurus can also make occasional apparitions.

Common inaccuracies in sauropod portraits

If a writer relies on pre-Renaissance science, a featured sauropod is up to its armpits in water and living in swamps while lazily munching some swamp weeds. Before The '70s, the dominant but incorrect hypothesis said they needed to spend most of their time in water to support their massive bulk and to escape the (allegedly) non-swimming theropods. Modern science says sauropods were terrestrial (though able to swim in an elephant style if needed); note  if they were really swamp-specialists, they would have had a high chance of slipping in the mud with fatal consequences. If lucky enough to survive the fall, they'd starve to death from lack of nutritious food, because swamp weeds are very poor in nutrients. With their bodies submerged, their ribcages wouldn't even be capable of expanding due to water pressure, suffocating them. And the alleged weakness of their teeth and the high placement of their nasal openings are not real proof for an amphibious, swamp weed-eating lifestyle.note  Finally, footprints show carnivorous dinosaurs were capable of swimming using their hindlegs (as shown by the aforementioned alleged Dilophosaurus footprints), making the sauropods' fleeing in water to escape them potentially useless.

Among other mistakes when portraying sauropods, one very common is to show them with elephant-like nails or hooves, falling straight in Most Writers Are Mammals. Actually, sauropods had true claws. They usually had a thumb-claw on each forefoot (which was narrower than in modern elephants) and three claws on each hindfoot (which was broader and more elephant-like than the forefoot). Even so, in most portrayals that do show clawed sauropods, they usually have four or five claws on each foot. More related to Reptiles Are Abhorrent is the tendency of depicting sauropods' necks and tails as serpentine: you'll even find brontosaurs using their necks like snakes when attacking their prey. Actually, their necks had relatively few vertebrae, like a giraffe's, and were relatively stiff, especially if compared with their flexible (but not serpentine) tails, which often had 50-70 or more bones. In the oldest scientific depictions, sauropods were often shown with splayed limbs, not pillar-like, and crawling a bit like a giant tortoise. Recently, a new study suggests that, due to the way their teeth are preserved, sauropods had a keratin covering on their mouths forming into a beak-like structure, instead of fleshy lips or toothy grins as always depicted.

Thunder dinosaur or deceptive dinosaur?: Apatosaurus and Brontosaurus ***

Both lived in the Late Jurassic (154 to 150 million years ago) in what is now the USA. They were basically identical in shape: both were large but less than other sauropods, 75 ft/23 m long and weighing at least 23 metric tons (equal to roughly four elephants). The neck made up about a quarter of their total length, the tail about half. Their overall size is often exaggerated in popular writing, for instance by claiming that Brontosaurus weighed as much as 10 elephants, or even that it was the largest dinosaur (one could assume the writer knew only one type of sauropod).

The head was small and slender; the teeth were peg-like and found only at the tips of the jaws. The neck had more than 10 vertebrae, and was of average length but wider than in other sauropods. The body was stocky and deep; the hips were taller than the shoulders. The legs were robust (even more so than in most sauropods), the hindlimbs longer than the forelimbs. The tail was very long (about 80 vertebrae), thin and whiplike near the end.

Apatosaurus is one of the few sauropod genera already known to science when dinosaurs entered pop culture in the 1900s. Marsh described the first species in 1877, in full Bone Wars context, but its first remains were incomplete. Just two years later Marsh described a second alleged Apatosaurus species as a distinct animal, Brontosaurus. The latter became the iconic image of a sauropod for most the 1900s. Brontosaurus and Tyrannosaurus were the ultimate stock dinosaurs in their respective roles as herbivore and carnivore, and contenders for the title of THE overall most iconic dinosaur. In classic dino-stories the brontosaur's designated role is the Gentle Giant (while T. rex is the Big Bad, Stegosaurus the dumb dino, Triceratops the badass or The Hero, the hadrosaurs the Stock Fodder)... unless Everything is Trying to Kill You, of course. In the classic version of King Kong, brontosaurs are meat eaters.

Why has Apatosaurus long been considered the only correct name for this pair of dinosaurs? Because scientific rules say if one animal is assigned two scientific names, only the first one is valid, and "Apatosaurus" was coined two years before "Brontosaurus". The latter means "thunder lizard" (probably a reference to the booming sounds sauropods might have made when walking), while the former means "deceptive lizard" — a much less cool name but, surpisingly, the most apt one.

And then, why has just Brontosaurus been the traditionally most popular sauropod, despite being smaller than Brachiosaurus and shorter than Diplodocus? Probably because the first-ever mounted display of a sauropod skeleton (erected at the American Museum of Natural History in 1905) was based on a mostly complete Apatosaurus skeleton, with missing parts borrowed from other sauropod specimens, which also gave the display skeleton a short, boxy head and blunt tail, both incorrect. However, the Museum chose to label the display "Brontosaurus". Other museums followed suit with similar Brontosaurus displays. Popular writing and dino-art kept spreading the at-the-time incorrect name, and the ghost of Brontosaurus still haunts Apatosaurus, as does the image of the short, round head — even though the long-narrow-head portrayal is starting to become more known among general public. note 

Peter Jackson's King Kong (2005) referenced this situation by having a newly-discovered dinosaur on Kong Island be named Brontosaurus in the special features on the DVD. A nice homage, but in reality, once a name is used, even if it's invalidated, it can never be used again for a new animal, lest later researchers be left with no idea which Brontosaurus you're talking about.

Even though the name "Apatosaurus" is today more known among common people than before thanks to documentary media, it could fall again in oblivion if recent proposals are confirmed in the next few years. Since the early 20th century the genus Apatosaurus has traditionally included Apatosaurus ajax (the first described species), Apatosaurus excelsus (excelsus = elevated), and Apatosaurus louisae, plus two lesser-known, recently-identified species. However, in 2015, a new study re-classified Apatosaurus excelsus and the two recently-identified species in the genus Brontosaurus after finding differences between "Apatosaurus" excelsus and the type species of Apatosaurus, A. ajax. If further studies ultimately confirm this proposal, both genus names will be validated, with the more famous species becoming Brontosaurus once again.

Winsor McCay's famous 1914 Gertie the Dinosaur made Brontosaurus the very first dinosaur in cinema, and the very first character deliberately created for a cartoon. Interestingly, she's shown as a land animal, anticipating a largely-discarded theory for more than half a century. Gertie is basically portrayed like a domesticated elephant, and, interestingly, has the correct head shape for a brontosaur: since the brontosaurian head was considered round at the time, some hypothesize she's actually meant to be a Diplodocus.

  1. Entry Time: 1905
  2. Trope Maker: Display at American Museum of Natural History (as Brontosaurus)

The "longest": Diplodocus **

Living in western North America during the Late Jurassic Period (154-150 million years ago), Diplodocus was a neighbor of Brontosaurus & Apatosaurus. These three dinosaurs belonged to the same family, Diplodocidae, and many features of Brontosaurus & Apatosaurus (the whip-like tail, the skull shape, and the longer hindlimbs) are shared by Diplodocus. Unlike the bronto/apato's ones, Diplodocus' portraits have always had a narrow-ended tail and the long head with a flattened snout typical of diplodocids (the Diplodocus' skull and tail-end have been known since the first discoveries). This means the two animals can be easily distinguished from each other in older media. note 

In more updated depictions, their overall profiles are the main key to telling Diplodocus from Brontosaurus. note  The diplodocuses were longer than the apatosaurs and the brontosaurs, from about 80 ft/24 m to 115 ft/35 m, but weighed only about half as much (10-16 metric tons). The Diplodocus shape was more slender and elegant than the robust Apatosaurus & Brontosaurus, with a longer, slimmer neck; these differences allowed the animals to live side-by-side and avoid competition by browsing different kind of vegetation, since the diplodocus was able to reach higher tree-food. Diplodocus has classically been qualified as "the longest dinosaur", but this record is now contended by other diplodocids, like Supersaurus.

All diplodocid sauropods had long tails, but Diplodocus took this to an extreme. Its tail was 14 m long, longer than a whole T. rex! note  It has been speculated that the thin end of the diplodocids' tail could have been used as a whip directly against threats, or indirectly by making whip-cracking sounds. The tail vertebrae also had double beams (hence the name Diplodocus: "double beam") that may have protected the blood vessels inside the tail when the tail pressed against the ground. Diplodocid sauropods may have used their tails as a support together with their hindlimbs, lifting their forequarters to reach higher vegetation.

Found during the Bone Wars like Apatosaurus and Brontosaurus, Diplodocus was introduced to the public courtesy of Andrew Carnegie some decades later. He sponsored an expedition that discovered a new Diplodocus species (which was named Diplodocus carnegii), note  and had the remains mounted in his museum in Pittsburgh. He then donated replicas of it to museums all over the world; as a result, in some European nations (especially Britain) Diplodocus became the iconic sauropod, rather than "Brontosaurus" as in the USA.

In recent years, the British Speculative Documentary Walking with Dinosaurs has popularized some recent theories about Diplodocus and sauropods in general: the straight, horizontal neck posture and the iguana-like spiky back. The first is due to analysis of the neck vertebrae using computer models; note  the second arose from a discovery made in the 1990s of a diplo with imprints of horny spikes near its back. Both theories are now disputed: both the base and the end of the sauropods' necks were more flexible, and the animals may have been able to fold their necks and lift them like most modern long-necked animals. The spikes were dermic structures not related to the skeleton; dinosaurs being closer to birds than to lizards, the structures might have been spread over the animal's back like theropod feathers, instead of in a single line like an iguana's. We don't know if other sauropods had spikes, but spiky longnecks are now a common sight in books and art — as it seems, dino-artists have hard work getting rid of the Dinosaurs Are Dragons idea even today.

  1. Entry Time: 1905
  2. Trope Maker: Carnegie Museum skeleton and subsequent replicas

The "tallest": Brachiosaurus in the former sense **

This is the third member of the iconic sauropod Power Trio and lived along Bronto/Apatosaurus and Diplodocus in Late Jurassic North America, 154-153 mya, but also (allegedly) in Africa in the same period. This detail was mentioned as a concrete proof about the Pangaea hypothesis, as brachiosaurs weren't able to cross oceans to migrate from one landmass to another. (The continents were still not completely separated from each other in the Jurassic.)

From its first description at the start of the 20th century, Brachiosaurus was considered "The biggest land animal ever!" until real or alleged new sauropods were described starting in the 1970s (see below). Of course, works made after The '70s may still qualify the brachiosaur in this way (sadly, among them, even Walking with Dinosaurs, at least the original series). Generally thought to weigh between 30 and 50 tons, Brachiosaurus has often been oversized in popular books, so far as to triple its size up to 130 tons, which would make it heavier than any animal alive today, except for the blue whale.

Brachiosaurs are visually distinct from diplodocids in several ways. First, their necks were noticeably longer than their tails, and their backs sloped backwards instead of forwards. Going into more detail, their tails had a thicker end lacking any "whip"; their necks were stronger, had more vertebrae and were held more vertically, like a giraffe; their teeth bordered most of their jaws and were chisel-like; their nasal openings were unfused, placed more forward, and were much wider than diplodocids' (the brachiosaur subgroup of sauropods, "Macronarians", just means "large nostrils").note  Finally, brachiosaurs are almost the only non-bird dinosaurs with forelimbs longer than hindlimbs (Brachiosaurus means "arm lizard"). Sometimes these difference get glossed over in popular media, which may show brachiosaurs with diplodocid heads, necks, bodies, legs, and tails. In these cases, they might be recognizable as brachiosaurs only thanks to a more upright body-shape.

As with other sauropods, brachiosaurs was associated with water in older reconstructions. To accommodate its upright shape, Brachiosaurus was often shown totally submerged in lakes, with only its head and, sometimes, only its nostrils above the water level, making its neck like a giant snorkel. Needless to say, this is quite unrealistic. In modern portrayals, Brachiosaurus has often been described as a "prehistoric giraffe" capable of browsing the highest vegetation that other sauropods were not capable of reaching — unless diplodocids were able to stand upright on their hindlegs. Brachiosaurs probably weren’t capable of that, having their center of gravity much farther forward, and their shorter tails didn't provide support (they would only bring a little bit of extra reach anyway). Moreover, as their greater size could have automatically protected adults even against the biggest predators, they probably didn't need to lift their forebody and use the front-legs to fight an Allosaurus, nor didn't they need to use their short tail to hit it to death (Diplodocus and Apatosaurus probably did both of these).

However, in fictional (and sometimes even documentary) media, brachiosaurs show unusual athletic skills: in Jurassic Park, a brachiosaur rears up on its hindlegs to reach a tiny branch. In Disney's Dinosaur, the brachiosaur Baylene is able to remain in a fully erect position for 30 seconds to break the wall of a cave with her forefeet. Also in Jurassic Park, a brachiosaur is shown with an oversized head with fleshy lips, chewing vegetation like a cow. Sauropods didn't chew: their teeth were more suited to cutting plant material (in the case of the brachiosaur), or to raking it like a comb (like the diplodocids).

Strangely, before the '90s Brachiosaurus was an unusual sight in cinema, much rarer than "Brontosaurus" and Diplodocus despite its record size. note  Then, in 1993, Spielberg made a brachiosaur the solemn show-opener of his first film (Crichton's eponymous novel had Apatosaurus in this role). Thanks to this (and possibly to its cooler look), the brachiosaur has perhaps become the most frequent longneck in popular works since then, and many "young" dino-fans now consider it THE iconic sauropod in pop culture (sometimes even using the word "brachiosaur" generically as if it were a synonym of "sauropod"), while pre-JP dino-fans still tend to think of "Brontosaurus" (in the USA) or Diplodocus (in Britain) in these roles — of course this is a very rough distinction, since all three dinosaurs are actually very popular in every country.

Sadly, Brachiosaurus recently also went through some naming troubles, but its situation isn't as severe as the traditional Apatosaurus-Brontosaurus deal — the name Brachiosaurus remains valid, however its best-known species, B. brancai, had to be placed in a different genus, named Giraffatitan. note  Giraffatitan ("titanic giraffe") was found in Africa in the Tendaguru site two decades after the U.S. brachiosaur, and is known from complete remains which show a distinctive domed skull. An impressive, 12 m tall Giraffatitan skeleton was mounted in the Berlin museum in the 1930s: this was the biggest mounted dino-skeleton until two decades ago, and the model of the popular image of the brachiosaur lasted for decades. On the other hand, the valid Brachiosaurus was long known only from fragments, and its skull was described only few years ago. This skull, which had a smaller dome than Giraffatitan's, was long classified as another kind of sauropod, Camarasaurus (see below); ironically, it was just this skull that was put in the original "Brontosaurus" skeleton. The old pop-cultural "brontosaur" is just a Mix-and-Match Critter made of Apatosaurus and Brachiosaurus.

  1. Entry Time: 1930s
  2. Trope Maker: Berlin Natural History Museum (now recognized as Giraffatitan)

The "heaviest": Argentinosaurus *

Argentinosaurus was discovered in Argentina in 1993. It lived in the Early Cretaceous, 95 mya, unlike the more famous sauropods, the diplodocids and brachiosaurids, which lived earlier during the Jurassic. Argentinosaurus belonged to a group of sauropods called titanosaurs, which evolved within the Titanosauriformes (which included Brachiosaurus) and replaced the earlier sauropods worldwide in the Cretaceous.

Titanosaurs are based on the genus Titanosaurus, which was first described in 1877 and used as a "wastebin taxon" since then. The classification of titanosaur genera is still in debate and many (including Argentinosaurus) are based on fragmentary remains note . New finds and further cladistic research may still change the descriptions of these animals. Titanosaurs seem to have been more compact than earlier sauropods, with shorter necks and tails, solid bones, and wider frames. At least some titanosaurs had crocodile-like skin armor; in one case (Saltasaurus, see below) this was fully developed as bony plates similar to Ankylosaurus. On the other hand, Argentinosaurus probably didn't develop an armored skin.

Length and weight estimations of Argentinosaurus are necessarily speculative, but the consensus seems to put the length at 98 ft/30 m (like Diplodocus) and the weight at about 73 metric tons (about twice a Brachiosaurus). Few people know, however, that another South American titanosaur, Antarctosaurus, has left some possible remains almost the same size of the argentinosaur, which were found several decades before 1993. Being very scant and dubious, they have been largely ignored. Other sauropods were previously estimated as even heavier than 73 tons (see the following section) but these valuations appear positively exaggerated. Such heavy land animals would haven't even able to survive, and the blue whale still remains the official record-holder of all time (only other sea creatures could have overweighed it in the past).

In 2002, Chased By Dinosaurs featured a herd of Argentinosaurus. In a memorable scene, Nigel Marven hurries to place weight sensors in front of the herd as it approaches, walking straight towards the camera and messing with the viewer's perspective: a very effective demonstration of the immense size of these animals. Strangely, unlike its predator Giganotosaurusnote Argentinosaurus has not received much attention in fiction since then. Maybe because, size-related impressiveness apart, the Argentinosaurus here do nothing sensational — the adults continue to walk apparently unmoved after the Giganotosaurus bring down one of their young. On the other hand, Argentinosaurus became popular among dino-fans for being described as "the biggest ever dinosaur" in the show and in the dino-books of the last decades. But this is not an isolated case. Several other sauropods have at one point been described the same way since the very first sauropod discoveries. One of the first was Atlantosaurus "Atlas lizard". Many others followed since then, with scientists seemingly competing with each other for who coined the most awesome nameArgentinosaurus is one of the rare exceptions, meaning simply "lizard from Argentina".

  1. Entry Time: 2002
  2. Trope Maker: Chased by Dinosaurs

Size matters *

Let's face it — paleontologists are people too. While they carefully excavate fossils in some dusty badlands location, or sort through boxes of collected fossils in chilly museum basements, they can't help but secretly hope to be the one who discovers or describes Badassosaurus mynamii. Sometimes they do strike gold. Most of the time, they report an unremarkable animal and get the satisfaction of a job well done but very little glory. Then, there are cases like these...

  • Ultrasaurus the "Ultra-lizard" is a story written across The '80s and The '90s about two sets of bones and one name. The U.S. set (a bit of backbone and a shoulder girdle, from Colorado) was in 1979 described by James Jensen as Ultrasaurus, the largest dinosaur ever... to the press, not in a scientific paper. It was depicted as a brachiosaurid 30 m long, 16 m tall and with a weight up to 130 tons, making it even bigger than the former record-holder, Supersaurus (which, by the way, was also described by Jensen a bunch of year before, always in Colorado). The South Korean set (a bit of backbone and an upper forearm) was described a few years later as an Ultrasaurus. This, however, prevented the U.S. animal from being called Ultrasaurus officially, so they had to settle for "Ultrasauros" in 1991. It was still the largest dinosaur, though. Well, at least for a few years, until it was realized that the U.S. set of bones was actually from two different animals, a Supersaurus and a Brachiosaurus: the name "Ultrasauros" was consequently discarded in favor of Supersaurus. Before that the U.S. ultrasaur showed up in some documentaries, and is cited in Calvin and Hobbes as well as in the first JP novel (which mentions the following example, too).

  • "Seismosaurus". In the early 1990s Ultrasaurus had to face a rival for "the biggest" title: the "Seismic lizard", popularly nicknamed the "Earth-Shaker". A diplodocid from New Mexico with an estimated length of 177 ft/54 m and an estimated weight of 112 tons, which makes it almost twice as long as a blue whale, and almost two thirds of the blue whale's weight. Impressive? Well, when other experts got a look at it they determined that the size calculation had been thrown off by misplaced vertebrae, that 95-110 ft/29-33 m was a more accurate estimation, and, more recently, that the seismosaur was simply an old, well-grown Diplodocus. The name Seismosaurus is now discarded.

  • Supersaurus the "Super-lizard", as said above, was found in Colorado in the 1970s. It was described from a few bones as a brachiosaurid of unusual size, twice as long as Brachiosaurus, and hailed as the first sauropod "bigger than the brachiosaur". When more remains were found, Supersaurus was reclassified as a diplodocid, longer and more massive than those previously known but not excessively so. However, an analysis of the fossils in 2016 suggests that, like Seismosaurus, it also might simply be an overgrown specimen of a better-known dinosaur—Barosaurus, in this case (see below).

  • Sauroposeidon (the god Poseidon was also known as the "Earth Shaker", geddit?) was described in 2000 based on four extremely elongated neck vertebrae found in Oklahoma (which were, incidentally, first thought to be petrified logs). If it was a brachiosaurid, it might have had the longest neck of every creature ever (even longer than the neck of Mamenchisaurus, see below). However, data published in 2012 puts it closer to the titanosaurs. Living in Early Cretaceous USA along with Deinonychus, some portrayals have depicted deinonychosaurs bringing down adult Sauroposeidon.

  • Paralititan ("titan of the swamps") is one of the several newly-found titanosaurians cited as possible contenders of Argentinosaurus for "the biggest" title (others are Puertasaurus, Dreadnoughtus, Notocolossus, Patagotitan, Alamosaurus etc., see Prehistoric Life - Sauropods). From the same habitat as Spinosaurus, it is known from a bit of backbone, a shoulder girdle, and an upper forearm. By comparing the bones with the skeleton of a more complete titanosaurid such as Saltasaurus, Paralititan appears to have been 85 ft/26 m in length and have weighed 59 metric tons. You know, unless it turns out to be a mistake.

  • Bruhathkayosaurus. Found in India in the 1990s, this one is, for now, the Up to Eleven example. Described as a titanosaurian sauropod and believed to have weighed 126 metric tons, it was until recently estimated at up to 220 tons, even heavier than the blue whale. However, its formal description is extremely inadequate, and it is speculated that the leg and hip bones found are actually petrified wood. But this is not all: our exotic-named giant was initially regarded as a theropod. Imagine a carnivorous dinosaur 50 times heavier than a T. rex... Unfortunately, Bruhathkayosaurus must now join Amphicoelias below as another "one that got away"; it seems that its bones were never properly stored out of the elements and got washed away during rainstorms.

  • Amphicoelias fragillimus was believed to be a diplodocid that would have been 190 ft/58 m long, and weighed 120 metric tons (making Diplodocus look like a Labrador retriever in comparison)… but the only find since 1878 is a single vertebra, which has been lost. note  This discovery was largely forgotten until its original description made by Edward Cope became more widely-known in the last decade, at least in Internet circles. However, a more thorough analysis of the vertebra in 2018, based on surviving drawings, suggests that Amphicoelias was not a diplodocid at all, but a member of a different family called the rebbachisaurids. These dinosaurs had very big vertebrae in proportion to their bodies, so if it was a rebbachisaurid, Amphicoelias might not have been the largest dinosaur after all, although still very large (over thirty metres long and seven metres tall at the hip).

So, which one is the biggest? Depends on the chosen criteria.

  • The Longest: Amphicoelias if it was a diplodocid; Diplodocus-Barosaurus-Supersaurus-another diplodocid otherwise.
  • The Tallest: Sauroposeidon if it was a brachiosaurid; Brachiosaurus-Giraffatitan-another brachiosaurid otherwise.
  • The Heaviest: Bruhathkayosaurus if it really existed; Argentinosaurus-Alamosaurus-Puertasaurus-another titanosaurian otherwise.

Good luck to all of you bone-diggers out there.

  1. Entry Time: 1970s
  2. Trope Maker: Sensationalism in media and wishful thinking among paleontologists.

The "most common": Camarasaurus *

Who's the most common sauropod in the USA, Apato/Brontosaurus, Brachiosaurus, or Diplodocus? None of them. It was Camarasaurus. note 

This dinosaur was as enormous as the former (18 meters long, a bit shorter than an apatosaur but with the same bulk), and shared their same habitat in which other two popular dinosaurs lived, Stegosaurus and Allosaurus; and yet, when was the last time you’ve heard “Camarasaurus” in a film/cartoon/comic? Even the famous Speculative Documentary Walking with Dinosaurs has totally ignored it, preferring its Great-Stock cousins instead. The misfortune of Camarasaurus is probably due to not detaining any size-record among sauropods: it has never been either “the longest” like Diplodocus, or “the tallest/heaviest” like Brachiosaurus. Furthermore, its first complete skeleton (found in the early XX century in the Dinosaur National Monument between Utah and Colorado) was from a juvenile, leading some books telling the camarasaur was "one of the smallest sauropods". On the other hand, other dino-book have said this dinosaur was 40 m (130 ft long) long and that was "one of the biggest dinosaurs"!

Discovered during the Bone Wars, Camarasaurus is considered by some a rather unsauropod-like sauropod, because of its relatively large head and its much-shorter neck compared to most other sauropods. It tended to be confused with “Brontosaurus” in the past, because the classic brontosaur portraits have a round head and a short, blunt tail, just like Real Life camarasaurs. Until few years ago, the head and tail of the skeleton at the base of the popular "brontosaur" image were believed belonging actually to a specimen of the "camara", so in old books it's classically said "The brontosaur's traditional pictures have the head of Camarasaurus". note 

However, Camarasaurus was more related to Brachiosaurus than to Apatosaurus. Both the brachiosaur and the camarasaur had short, boxy skull with wide nasal openings, a nasal crest, and relatively large teeth which bordered the whole jaws - the Diplodocus and Apatosaurus skull was longer and flatter with peg-like teeth only on the jaw-tips. The four legs of Camarasaurus were about the same length, and its back was perfectly horizontal and perhaps even a bit taller on the shoulders: Apatosaurus and Diplodocus has shorter forelimbs than hindlimbs, and their back had a convex silhouette with the tallest point on the hips. With its short neck, Camarasaurus arguably ate lower tree-vegetation than diplodocids and brachiosaurs; we don't know if it was able to lift on its hindlegs and tail to reach higher foliage, being its barycenter more forward than diplodocids, but more backward than brachiosaurs. Even though its tail lacked a "whip" end, it was comparatively longer than a brachiosaur's, and could have been used to hit predators as defense like what diplodocids probably did.

  1. Entry Time: 1905
  2. Trope Maker: its alleged skull placed on the first "brontosaur" skeleton

The "longest-necked": Mamenchisaurus *

What is the thing that has really made sauropods the most iconic plant-eating dinosaurs? Their size, useless to say. But there are few doubts that their unbelievably long necks have done their part, too.

But wait: if you think Brachiosaurus and Diplodocus have disproportionately vast necks, is only because you’ve never seen their Chinese cousin: Mamenchisaurus. The latter’s neck was so long that, if the animal would be still alive today, we could see it drinking some water from a lake with its forelimbs placed 12 m (40 ft) or even 15 m (50 ft) from the shore! In other words: the neck of Mamenchisaurus was longer than a whole T. rex was from nose to tail. This record has made Mamenchisaurus one of the most famed sauropods as well as one of the most classic Chinese dinosaurs. note .

Mamenchisaurus lived in the same age of the other stock sauropods (Late Jurassic), but was discovered in 1954, much later than them. Initially believed a close Diplodocus relative, now is thought a more archaic kind of sauropod which incidentally reached a similar shape, though with a much shorter tail not ending with a "whip" but with a small club (the "club" is a very recent discovery, and almost every mamenchisaur depiction show it clubless). Since the head of Mamenchisaurus has long been unknown, the most classic portraits show it with an inaccurate Diplodocus-like head; actually Mamenchisaurus head was more similar to Camarasaurus. In short, the polar opposite of what has happened to the allegedly boxy Apatosaurus head.

To date, the only significative apparition Mamenchisaurus has made in pop-culture was a simple cameo in The Lost World: Jurassic Park, where it's unidentified and unnamed, but it is very common in popular dinosaur book because of the size of its neck.

  1. Entry Time: 1997
  2. Trope Maker: The Lost World: Jurassic Park

The Armored Brontosaur: Saltasaurus *

When we think about “armored” dinosaurs, our mind automatically goes to things such as Stegosaurus, Triceratops, Ankylosaurus. Thus, if you are a layman, you could be astonished if we tell you that there were also an armored sauropod. Scientists themselves were surprised when such an animal was really discovered in 1980 in the Argentinian province of Salta: they called it Saltasaurus loricatus, meaning "the armored lizard of Salta". It walked around 80 million years after the more popular "three stock sauropod band", almost managing to see the meteor.

Saltasaurus armor was different-looking than Ankylosaurus armor. It had no spikes, and was made by several small round bony scutes of two different size, covering all the upper parts of its torso like a mosaic (some portraits wrongly show this armor covering also the upper neck and tail). Though apparently much lighter than an ankylosaur’s, it would have been enough to defend the sauropod against predators like the contemporary “horned” Carnotaurus.

The scientific importance of Saltasaurus raised up even more after the discovery (made at the end of the 1990s) of a fossilized breeding-site full of nests and hatchlings, the very first known from a sauropod. These remains were attributed to Saltasaurus, but we are not sure if they pertain to its genus. Saltasaurus is also a member of that subgroup of sauropods called titanosaurs: since its discovery, armor plates of several other titanosaurs have since been found, although more incomplete. note 

Saltasaurus was also considerably smaller than all the sauropods above: it was "only" 12 m long and not much heavier than an elephant. Not counting the bony plates, its shape was that of a generic sauropod, with forelegs shorter than hindlegs and middle-length neck and tail. Despite its badass-look given by its armor, Saltasaurus still remains a non-fictional animal (unlike Carnotaurus), but could enter the fiction work in the future nonetheless.

  1. Entry Time: 2003
  2. Trope Maker: Dinosaur Planet

A Whale of Dinosaur: Cetiosaurus *

Which were the biggest animals ever, whales or dinosaurs? Hard question, depends on what criterium you want to use. If you count the length some sauropods could have been even longer than any known whale (blue whale included!), but were still shorter than some modern invertebrates such as the giant ribbonworm Lineus longissimus or some jellyfish (better, their tentacles). If you count the mass, whales probably are still bigger than every dinosaur.

Cetiosaurus, the first sauropod ever described, just means “whale-lizard”, but this is not a mere reference to its size (18 m, a bit shorter than Apatosaurus but with about the same weight); it was literally believed a whale-thing at one point. First found in 1842 in England slightly after Richard Owen coined the word “dinosaur”, its first remains were so incomplete that Owen couldn’t believe such a heavy animal could live on land. Since limb bones were missing, he thought the owner was a non-dinosaurian marine reptile (remember sea-reptiles were already very well-known at the time). When the limb bones were discovered several decades after, the familiar image of an elephantine “reptile” with long neck and tail came to light. Though not a Wastebin-taxon like Megalosaurus and Iguanodon, Cetiosaurus could be seen as their sauropodian equivalent - incidentally, lived just alongside Megalosaurus in Middle Jurassic Europe, but some possible remains traditionally classified as Cetiosaurus have been found in Africa too, more precisely Morocco.

Cetiosaurus has been the archetypical “basal” sauropod in popular dinosaur books, and lived before the Stock Trio, 20/30 million years before them. Among the cetiosaur's primitive traits, it had a more generic skull and teeth than a diplodocid or a brachiosaurid, a tail of middle size, and above all compact vertebrae instead of hollow - cavities in the backbone is a typical feature of more evolved sauropods like Apatosaurus, Diplodocus, Brachiosaurus and Camarasaurus (the latter’s name just meaning lizard with cavities). These sauropods were discovered in North America just in the period of the cetiosaur’s correct interpretation.

The cetiosaur's very generic look, with no external traits that would make it recognizable, seemingly means it's predestined to remain an only-book animal - expecially British books, as it could be qualified the "national" UK sauropod. But it' worthy noting that Cetiosaurus was actually originally intended to appear in the british series Walking with Dinosaurs next to the contemporary carnivore Eustreptospondylus in the "Cruel Sea" episode dedicated to marine reptiles, but then producers changed their idea before broadcasting the show for some reason.

  1. Entry Time: uncertain
  2. Trope Maker: its status as the "British Sauropod" for excellence

Eight Hearts?: Barosaurus *

Overshadowed by Awesome seems a common trope among dinosaurs. We see a dinosaur, remain struck by its awesomeness… but later, another similar yet even cooler dinosaur takes its place in our mind. Barosaurus could be an example. 8/9 m long, its neck was one of the longest in the whole Animal Kingdom... but is definitively overshadowed by the 12/15 m long neck of Mamenchisaurus (as well as that of the brachiosaurs).

Discovered in the USA at the end of the Bone Wars, Barosaurus was one of the closest relative of Diplodocus, and lived as well in Late Jurassic North America; some possible remains from Africa are also known, but are generally thought to be from a different genus, Tornieria. Barosaurus was virtually identical to Diplodocus except for its shorter tail counterbalanced by the longer neck. Its was one of the longest sauropods, only a bit shorter than Diplodocus. Barosaurus means “heavy lizard”: though apt for a sauropod, it's not totally appropriate. Having the same slender frame of Diplodocus, the barosaur weighed less than other sauropods.

The Barosaurus lower notoriety is probably due to the fact that its remains have been less abundant than the Diplodocus ones. However, Barosaurus has gained more fame when a barosaur skeleton was mounted in the American Museum of Natural History in the 1980s. This skeleton is the dino-star of the museum, being mounted erected on the hindlimbs and the tail; 15 m tall, is shown defending its youngster from an attacking Allosaurus. In the same years, one bizarre suggestion was made about its physiology: with such a long neck, Barosaurus may have had eight hearts to pump blood up to its lofty head. These "hearts" were imagined to be placed through the neck, and pulsating synchronically to enhance the blood circulation. There could actually be a bit of reality in this idea: pulsating blood vessels are not unknown in the modern animal world. The problem is... there isn’t any evidence to prove all this true on Barosaurus.

Thanks to a very recent reinterpretation of a neck vertebra previously assigned to Supersaurus, Barosaurus now even enters the ring for "biggest sauropod" title. This single vertebra alone is over four feet in length, and seems to have belonged to an animal twice the size of other barosaur specimens. This would mean a creature within the ballpark of fifty metres (164 ft) in length and up to ninety metric tonnes if scaled isometrically, and assuming it was proportioned like the other specimens — its neck alone would have been seventeen metres long.

  1. Entry Time: 1980s
  2. Trope Maker: the erect skeleton mount in the New York Nature Museum

Other sauropods:

Sorry, these ones aren't here. If you're looking for Titanosaurus, Amargasaurus, Vulcanodon, Shunosaurus, and others, see here.

    Sauropod predecessors 

Prosauropod means "before the sauropods". Living in the Triassic or Early Jurassic periods, prosauropods were among the very first dinosaurs to appear, and the first dinosaurs to reach elephant size. Some of them may have been the ancestors of the sauropods. The name Prosauropoda isn't formally used nowadays (members of the group are now referred to as basal sauropodomorphs). Plateosaurus, considered the prototypical "sauropod predecessor", is the most common in the fossil record and one of the largest as well.

The "first giant": Plateosaurus *

Lived 216-199 million years ago, in the Triassic Period. Plateosaurus is one of the scientifically better-known dinosaurs, and also the most abundant dinosaur in European fossil record. More than 100 specimens are known, and even a "graveyard" in Southern Germany (Trossingen). Plateosaurus was also one of the first dinosaurs described, even before the word "dinosaur" was invented, but Owen didn’t include Plateosaurus in his new group (its first remains were very fragmentary). When the genus was being classified into Dinosauria, it was first placed in the theropod branch and thought carnivorous; later, was moved to the prosauropod group. A little-known curiosity is that an older synonym genus of Plateosaurus is just "Dinosaurus".

Its adult size was astonishingly variable, from 16 ft/4.8 m up to 33 ft/10 m, and its weight ranged from 600 kg to 4 metric tons. At a first glance, Plateosaurus looks like a cross between a diplodocid and a theropod. The general body shape was sauropod-like, with a small head, long neck, sturdy body, and long flexible tail (and also the typical thumb-claws). The limbs and stance were theropod-like; it was bipedal, walking on hind legs that were slightly folded, rather than pillar-like. The hindfeet had distinct digits with a claw on each. The neck was shorter and more flexible than a typical sauropod neck thanks to its shorter vertebrae, recalling the necks of some theropods a bit. The head was rather theropod-shaped too, but their teeth were small and blunt, apt to grabbing vegetation (without chewing) instead of tearing meat. The closer relationship with sauropods is betrayed by one detail: the hands and feet of the prosauropods had five digits each like sauropods, while true theropods lost the fifth digit both in their hands and their feet (except for the most primitive controversial theropods, like Herrerasaurus and its relatives, which had five digits on their hands/feet).

Science Marches On has been a strong factor within Plateosaurus portrayals. When believed a theropod it was depicted with a tripod stance like all large bipedal dinosaurs; one example could be in Fantasia. After being classified as a sauropod relative, the plateosaur has usually appeared as a slow quadruped but able to rear up its hindlegs like diplodocids, either to reach higher foliage or for defensive purpose (like in Walking with Dinosaurs). The exclusively bipedal portrait re-emerged only very recently, and today scientists believe Plateosaurus kept its body horizontally like theropods, and like them, was capable of relatively rapid runs if necessary. It may have defended itself with its thumbclaws, like what's believed about another not-related dinosaur, Iguanodon. The plateosaur's large size could have evolved to avoid predation by the carnivorous dinosaurs (which were still small and gracile at the time); the only predators that were possibly able to defeat the adults were basal archosaurs such as the contemporaneous Teratosaurus.

The two most-known Triassic dinosaurs, Plateosaurus and Coelophysis, are among the most abundant in fossil record but among the least common in pop culture. Plateosaurus appearances in fiction are very rare; in documentaries, it is usually shown only to emphasize the dinosaurs' "rise to power", as in the aforementioned Walking with Dinosaurs. Even though some Plateosaurus-looking dinosaurs occasionally crop up in TV (such as Dino), they are more likely humanized sauropods or Mix-and-Match Critter things.

  1. Entry Time: 1940
  2. Trope Maker: Fantasia

An old story: Anchisaurus *

Remember Dino, The Flintstonespet dinosaur? Its shape is very reminding of a prosauropod; more in particular, with its short limbs, it recalls this one: Anchisaurus — and some think the latter actually was the real inspirer of Dino. But this doesn’t means Dino is really an Anchisaurus… considering the writers’ great love for research he’s more probably a dog-like sauropod.

Despite its scarce fossil record, Anchisaurus is one of the most famed sauropod predecessors, thanks to its historical importance. It was the very first dinosaur ever discovered in North America (1818, six years before Megalosaurus). But was not recognized as a dinosaur at the time: this happened only during the Bone Wars sixty years later, thanks to Othniel Charles Marsh.

An Early Jurassic animal, thus more recent than the prototypical Plateosaurus, Anchisaurus was much smaller: only 9 ft long, about one third of an average plateosaur, and 50 times less-heavy. It was one of the most unsauropod-like “prosauropods”, with its rather short neck and limbs: its old quadrupedal portraits made it looking like a long-necked lizard (Anchisaurus means "almost-lizard"). Like all sauropodomorphs it had large curved thumbclaws for defense: unlike sauropods, however, Anchisaurus and the other prosauropods could have used them also as tools for grasping or cutting foliage, or for digging the soil in search of roots or insects. Talking about its modern classification: several scientists now think Anchisaurus, despite its primitive look, was a “near sauropod”, and some in the 2000s have even cited it as "the earliest sauropod". note  Some alleged Anchisaurus remains were once signaled from Southern Africa from the same epoch of Massospondylus, but they actually pertain to other kinds of prosauropods.

  1. Entry Time: 2001
  2. Trope Maker: When Dinosaurs Roamed America

Other sauropod predecessors

Sorry, these ones aren't here. If you're looking for Mussaurus, Massospondylus, Riojasaurus, and others, see here.

Armor-bodied plant-eaters

The Thyreophorans ("shield bearers"), were a group of dinosaurs notable for their body armor made of bony plates covered with horny sheaths. Many also developed weapons on the tips of their tails. All but the most primitive forms were massive quadrupedal animals belonging to one of these two groups: stegosaurians and ankylosaurians.


Stegosaurians were small-headed, mostly Jurassic herbivores that developed large bony plates along their backbone for uncertain purposes, and had pairs of spikes on their tail and sometimes on their hips or shoulders as well. Stegosaurus is the namesake of the group as well as one of the largest known members, while Kentrosaurus was one of the spikiest of them.

Plates as solar panels?: Stegosaurus ***

Lived in Late Jurassic North America, 155 to 150 million years ago, and was discovered during the Bone Wars like several other Stock Dinosaurs (Allosaurus, Diplodocus, Apatosaurus etc.) note  One of the most easily-recognized dinosaurs thanks to its bony plates, spiked tail and distinctive silhouette, Stegosaurus has always been one of the most iconic dinosaurs of all, along with T. rex, Triceratops, and a token sauropod. It is regularly portrayed both in films and in cartoons, though usually with a less important role in respect to sauropods and carnivores.

The several Stegosaurus species ranged from 24 ft/7.5 m up to 30 ft/9 m long, and weighed from 1.5 up to 5 metric tons. The two most known have been S. stenops (stenops = "narrow face") and S. ungulatus (ungulatus = "the hoofed one"). Its plates and deep body made it looking bigger than it was when seen from the side: actually, the stegosaur’s body was laterally-flattened, and not so heavy as it seems. Its limbs were pillar-like; the front legs were much shorter than hindlegs, and the neck was set low above the ground (but not the degree seen in old portraits). Despite its overall size, Stegosaurus had a remarkably small head, with room for only 2.8 oz/80 g of brain (often stated as "walnut-sized") note . This has made it the most iconic dinosaur within the Dumb Dinos trope (though sauropods are not far away). The small brain does not mean that stegosaurs and sauropods were witless, though. And they didn't have a secondary brain in their hip region as is often stated; the extra space there probably accommodated the nerves for the hindquarters.

The back plates were the most distinctive stegosaurian feature, but it isn't entirely clear what their purpose was. It was debated whether the plates were covered in horn or in skin, but a study on stegosaur skin impression suggests the former is more likely. Defense, thermoregulation, and display (mating or threat) are the classic hypotheses, but we haven’t definitive proof for any. The early theory that they were used for armor is the most unlikely: the plates were dermic structures not attached to the skeleton, and they were irregularly placed to be used as armor and would leave the animal's sides unprotected — although if covered in horn they might have had sharp edges, which would make them effective as defense. The "solar panel/radiator" theory was the most followed until recent years: it could explain why they apparently were so rich in blood vessels, and also the singular arrangement of these plates — they were asymmetrically-placed, giving more surface to solar rays. This theory is still a possibility, as studies on crocodilian scutes show they have usage for thermoregulartory purposes. Walking with Dinosaurs popularized the third theory, showing a Stegosaurus reddening its plates and scaring an Allosaurus away. However, if used for display, they might also have had the function of making the animal look larger or communicating with others of its kind.

Even the configuration of these plates was until recently debated. Though Stegosaurus has left dozens of specimens, they are usually found with misplaced plates, making them a sort of puzzle to rebuild. All combinations were proposed, from a single line to two paired lines. One early theory was they were flat on the back like tiles: this gave to the dinosaur the odd name Stegosaurus, "roof-lizard". The first still-articulated stegosaur skeleton was found only in the 1990s, and shows alternated plates, confirming most of the earlier suppositions.

Stegosaurus' tail was shorter than that of most sauropods: it was muscular and flexible, and the animal may have been able to rest it on the ground to assume a tripod stance and reach higher vegetation, just like what has been hypothized about the diplodocid sauropods (see above). When swung from side to side, this tail made a powerful weapon against enemies. Near the tip of the tail was a group of four long spikes known as the thagomizer, a term that originates from a Far Side cartoon, later adopted by the paleontological community (you can find it used in serious scientific publications) in an even more awesome case of Ascended Fanon than "raptors".

Another curiosity, though, is rarely mentioned: Stegosaurus had small scutes on its hips and tiny osteoderms under its throat. Also, a study on one Stegosaurus species, S. sulcatus, suggests that a spike found alongside a specimen may be actually from the shoulder and not from the tail as previously assumed. If this is true, then Stegosaurus had shoulder spikes like its relatives after all. Interestingly, one of the very first portraits of the stegosaur showed it with spikes all over its body and a bipedal posture.

It has recently been suggested that Stegosaurus was sexually dimorphic but others have cast doubts on this.

If you see Stegosaurus in popular media, don't be surprised to see inaccuracies. To this day, it may be shown with paired plates or even plates in a single line, instead of zigzagging in two lines, and they may be round or triangular instead of pentagonal. And its tail may have two, three, five, six, or even eight spikes,note  or none at all. These spikes may be shown as much shorter than in reality note . In some cases the neck is unrealistically long, like Dinny in Alley Oop, making it resemble a cross between a stegosaurian and a sauropod. The body may be shown as very low-slung and fat (even when seen from the front), and the legs are often stubby. Stegosaurus may often be depicted with a turtle-like face instead of a horse-shaped one like in real life. Occasionally, it is shown with a beak full of teeth or even worse, no beak.

In many old films, Stegosaurus is shown as a sorta "predestined loser" against big meat-eaters like Allosaurus, Ceratosaurus or Tyrannosaurus, being too slow to defend itself effectively. In modern portrayals, however, Stegosaurus more often wins fights with the aforementioned carnivores, like in Walking with Dinosaurs, as it is now considered to be agile and flexible in spite of its slow running speed and heavy body.

  1. Entry Time: 1912
  2. Trope Maker: The Lost World

My, how many spikes you have: Kentrosaurus *

If you're watching a film or even a TV documentary, good luck if you’ll ever find a stegosaurian which is not Stegosaurus. However, if you do, it will probably be Kentrosaurus.

Only half the length of Stegosaurus, 4 meters, and weighing much less than it, it was a small member of the family. Its overall body shape was almost identical to the latter... except for the armor. The usual plates on the neck and back were much smaller and paired (not zigzaging), gradually becoming spikes on the hip and ending with at least five pairs of true spikes on the tail. But this is not all, Kentrosaurus had also a pair of isolated spikes arising from its shoulders — to the point it could earn the nickname "porcupinosaur".

A Late Jurassic animal like Stegosaurus, Kentrosaurus was discovered in the 1910s in the same East African site along with much bigger dinosaurs like Giraffatitan and other sauropods, thus the two stegosaurians couldn't have met each other in reality. Dozens of Kentrosaurus skeletons have been discovered, but with plates/spikes scattered away (as usual among stegosaurs): thus, scientists once thought Kentrosaurus side spikes were on its hips instead of its shoulders. That's why classic dino-portrayals show it with spikes protruding from the pelvis instead of from its forequarters.

One mention about [mis-]spelling: Kentrosaurus should never be confused with Centrosaurus . Both names mean "pointed lizard", but the "points" of Centrosaurus were on its head: it was a ceratopsian. In some old sources Kentrosaurus is known as "Kentrurosaurus" ("pointed-tailed lizard"), but this name is now invalid.

  1. Entry Time: 1980s
  2. Trope Maker: Dino-Riders

The unpronounceable: Tuojiangosaurus *

Together with Kentrosaurus, the most portrayed non-Stegosaurus stegosaur in popular dino-books has been Tuojiangosaurus ("Tuojiang's lizard") — don't worry if you cannot pronounce that "jiang" correctly, unless you are Chinese or Chinese-speaking of course. It whole scientific name is Tuojiangosaurus multispinus, "many-spiked Tuojiang's lizard": it owes its name from Tuo-Jiang, a Chinese location within the Szechuan province of China. Other two classic Late Jurassic dinosaurs from the same country have also geographically-referenced names, Mamenchisaurus ("Ma-Men-Chi lizard") and the allosaur-relative Yangchuanosaurus, "lizard of Yang-Chuan".

Discovered in 1977 and described by paleontologist Dong Zhiming, Tuojiangosaurus was overall more similar to Stegosaurus than to Kentrosaurus (some quote it an its "Asian variant"), but was slightly smaller than its U.S. cousin: "only" 7 m long, like the smallest adult Stegosaurus individuals. Despite this, its armor was rather of an intermediate between a Kentrosaurus and a Stegosaurus one. Tuojiangosaurus had narrow, paired plates like the former, but a four tail-spiked (thagomizer) like the latter. The plates of the tuojiangosaur were like sharp isosceles triangles unlike the more pentagonal or "diamond-like" ones of Stegosaurus, and its tail-spikes were a bit smaller; some pictures show Tuojiangosaurus with shoulder-spikes like those of Kentrosaurus, but it is unsure whether it had them. Anyway, with such small plates, it is more uncertain that Tuojiangosaurus and Kentrosaurus would have used them as solar panels or radiators than the wider-plated Stegosaurus.

Tuojiangosaurus is one of the classic dinosaurs from Jurassic Asia: it seems especially common in British dino-books, as a skeleton cast of it has been on display in the Natural History Museum of London since the 1980s, which is often shown in illustrations.

  1. Entry Time: 1990s
  2. Trope Maker: the skeleton above in popular books

Other stegosaurians

Sorry, these ones aren't here. If you're looking for Huayangosaurus, Dacentrurus, Wuerhosaurus, and others, see here.


These are the most well-armored among all the dinosaurs (sometimes called the armored dinosaurs), with low wide frames, quadrupedal stance, strong short legs and armor consisting of bony plates covering the upper part of their bodies. They were herbivorous and mostly lived during the Cretaceous, after most stegosaurians. They aren't as common as the stegosaurians in works, but still crop up semi-regularly both in fiction and in documentaries.

Ankylosaurians were once divided in only two families: ankylosaurids (clubbed) and nodosaurids (club-less). Ankylosaurids (among them Ankylosaurus and Euoplocephalus) had a broad head, their armor plates formed a keratin-covered shell with short spikes in many directions, and they had a tail club except for the most primitive forms; proper nodosaurids had a narrow head, rows of osteoderms on their backs and flanks, and longer spikes jutting out sideways. In recent years a third subgroup has been recognized as distinct from nodosaurids: the polacanthids (named after Polacanthus), variably classified as either closer to ankylosaurids or to nodosaurids.

The Living Tank: Ankylosaurus **

Lived in North America around 66-65 million years ago alongside Tyrannosaurus, Triceratops, and the "duckbill" Edmontosaurus, at the end of the Dinosaur Age. Discovered in 1908 in Alberta, its actual size is uncertain, extimated from about 20 ft (6 m) long up to 9-10 m, but the latter is more likely: if so, it's the biggest known ankylosaurian, possibly weighing up to 6 metric tons (as much as a male African elephant), in the same weight range as Triceratops and the biggest Stegosauruses. Despite its size, its remains are quite scant, with still no complete skeletons found, and other relatives (for example Scolosaurus) are more common as fossils. Ankylosaurus' iconic status among ankylosaurians could be explained by its sheer size and because its own dinosaurian group is called by its name. Ankylosaurus was also one of the most strongly-armored ankylosaurians — several sources have described it as a "living tank".

Ankylosaurus has been famous since the 1940s as the Up to Eleven example of an armored dinosaur. In both fictional and documentary media it is often portrayed in a battle against T. rex (similarly to Triceratops). In these struggles the ankylosaur is seen defending itself by sheltering under its impenetrable bony armor, and using its tail-club like a Medieval mace, breaking the legs of its opponent and making it fall down. This might be Truth in Television, even though tyrannosaurs almost certainly didn't prey upon adult ankylosaurians frequently (hadrosaurs were much more abundants and armor-less). Despite their heavy build and short legs, they may have been able to charge the carnivore, since their limbs were not pillar-like as the sauropods and stegosaurs (and elephants), but more similar to those of a rhino or a hippo. Like stegosaurs, ankylosaurs tend today to be portrayed as more agile and active in fights now than in the past: in Walking with Dinosaurs one easily wins the struggle (despite being shown as a very slow-walking animal), delivering to the carnivore a fatal blow with its tail-mace. When the tyrannosaur is shown winning the battle, it's seen "overturning" the ankylosaur to expone the soft vulnerable underbelly and deliver the fatal bite there.

Most herbivorous or omnivorous dinosaurs are often depicted in media as gregarious animals: scenes involving herd-dwelling sauropods/ceratopsians/stegosaurs/hadrosaurs/iguanodonts/ornithomimids are a very common sight. On the other hand, adult ankylosaurians are always depicted as loners. This is realistic, though, because their fossils are more rare than those of other large herbivores and almost always found isolated. One rare exception is a group of about eight juvenile Pinacosaurus (see below) found together, which probably died at the same time during a sandstorm.

Ankylosaurus probably retains the sad record of being the worst-known Stock Dinosaur. Even in documentary works, its size, shape, and composition tend to be pictured incorrectly, often with traits from other ankylosaurian species. The incompleteness of the remains only partially justify this. One common mistake is to leave out the tail club, or to have it shaped incorrectly — for example, adding spikes to it. A famous example of the latter is the "Ankylosaurus" (actually a Scolosaurus) painted by Zdenek Burian defending itself against a tyrannosaurid: it is undersized and has two spikes on the tip of its tail. When based on Real Life fossils, the club usually appears two-lobed like that of a Euoplocephalus (a close relative commonly depicted in popular dino-books), instead of elliptical. The bony covering on its back should be a snugly fitting mix of large and small plates and be interspersed with short spikes. Many classic portrayals, on the other hand, show long spikes only on the sides, similar to the related nodosaurids. Other portraits go even further, showing totally spikeless Ankylosauruses (see the aforementioned finale of Walking with Dinosaurs). Finally, the broad head should have four horns behind the eyes and the ends of the mouth. Ironically, one of the few correctly-shaped ankylosaurs in cinema is the dog-like Url from Disney's Dinosaurs (he was highly undersized, but this may be justified if he was young). Many other inaccuracies seen in ankylosaur portrayals are substantially the same as the stegosaurs (see above).

Being related to each other, stegosaurs and ankylosaurs shared many features. They had the typical ornithischian jaws, with teeth only on the back and a toothless beak on the tip. However, their beaks and teeth were weaker than other ornithischians (ceratopsians, ornithopods); they may have chewed only soft plant material near the ground-level, and/or swallowed small stones to aid digestion, like sauropods. Even though were much smaller-sized, stegosaurians and ankylosaurians tend to be shown as slow-moving as the sauropods: ex. the aforementioned Url which has the slowest pace among all the dinosaurs of its herd (just as slow as its companion brachiosaur Baylene). Pre-Renaissance depictions used to portray ankylosaurians and other four-legged dinosaurs with splayed legs and dragging tails. Actually quadrupedal dinos had erect limbs (among them only sauropods had true claws, the others had blunt nails), and footprints show they usually kept their bodies and tails above the ground when walking around. Of course, expect to see splayed-limbed ankylosaurs even in relatively recent works — Rooter of The Land Before Time appears even slower than the sauropods of the same film (the latter have correct upright limbs, though).

  1. Entry Time: 1940s
  2. Trope Maker: "The Age of Reptiles" mural

Gimme the club: Euoplocephalus *

Ankylosaurus was the first clubtail recognized (1908), but, as said above, its remains were very scanty; however, its record size (more than 10 m long) soon made it the prototype of the ankylosaurians. But North America was home for other clubtails as well, which lived slightly earlier than the namesake of the group (though all lived in the Late Cretaceous): the traditionally most-portrayed among them has been Euoplocephalus ("well-armored head", NOT to be misspelled "Euplocephalus" or "Eurocephalus" or "Enoplocephalus" or so on).

Euoplocephalus lived 75 million years ago in Alberta (about 8 million years earlier than Ankylosaurus), was 6-7 meters long and weighed around 2-3 tons, about the same weight of the neighboring ceratopsids (Centrosaurus, Styracosaurus, Chasmosaurus etc.), but noticeably smaller than the more recent Ankylosaurus. note . Like Ankylosaurus, it too had armor plates arranged in rows along its back; but Euoplocephalus' armor was traditionally thought to be awesomely more complex, and may even be described as "artistic". A couple of flat bumps were on the neck, and two pointed spikes protruded from the shoulders. Several other spikes were placed in regular, elegant lines along its back. Even the elbows had three small round scutes each. The head was similar to Ankylosaurus, with mosaic-like scutes on its roof, four small horns, and bony eyelids. Finally, the club was trefoil-shaped and almost resembled the club of French playing cards. Some older drawings of Euoplocephalus show it with spikes sticking out from its tail club; this is based on an outdated interpretation of its relative Scolosaurus. Rooter, from The Land Before Time, is probably the most famous example of this.

A really cool animal to draw: in fact, Euoplocephalus appears as the actual stock ankylosaur in many dinosaur books. It's also worth noting that several alleged Ankylosaurus seen in books, documentaries and films tend to have some euoplocephalic traits, with conical horns instead of triangular, trefoil clubs instead of oval, and sometimes even the elbow scutes and the flat bumps on the neck. Despite this, Euoplocephalus is typically not portrayed in CGI documentaries, which will always prefer its gigantic cousin — the fact that Ankylosaurus could fight T. rex while "Euply" only had albertosaurs etc. to battle doesn’t help. Some dino-books wrongly portray Euoplocephalus living and fighting against Tyrannosaurus rex, which actually lived later.

  1. Entry Time: 2000s
  2. Trope Maker: The Lost World: Jurassic Park

Spiny yet clubless: Polacanthus *

Some decades later the discover of the first ankylosaurian in England, Hylaeosaurus, a companion was added to it: Polacanthus. English toonote , and also conviving with Iguanodon in the Early Cretaceous like Hylaeosaurus, Polacanthus was rather small compared to Ankylosaurus or Euoplocephalus (being 4 m long), and its first original remain found in the isle of Wight was very incomplete. This explains why in older depictions Polacanthus had very light armor, consisting only of pairs of long dorsal spikes (hence the name, "many spines"), a bony shield on its hips, and pairs of small triangular plates on the tail. Some portrayals took it a further step and gave it a stegosaur-like thagomizer. The spiked-tailed polacanth made cameo appearances in Planet of the Dinosaurs and the film adaptation of The Land That Time Forgot as well as a more prominent role in Dinosaurs as Robbie Sinclair's friend Spike. Today, thanks to a much more complete specimen found in the early 1990s in England, we know its armor was extensive and Ankylosaurus-like (though even spikier), but with no club-like tail. The polacanth appears with this new look in Walking with Dinosaurs as a follower of Iguanodon herds.

  1. Entry Time: 1970s
  2. Trope Maker: Planet of the Dinosaurs

Young struggling Dinosaurs: Pinacosaurus *

Many ankylosaurs are known from Asia. Pinacosaurus, the most common in fossil record, was basically the equivalent of Euoplocephalus above. Slightly smaller than it and with a much simpler armor than Scolosaurus, Pinacosaurus ("table-lizard") had also a narrower head, a hooked bill, different "horns", and a two-lobed club. The bigger but less-common Tarchia and Saichania were more similar to Ankylosaurus; the mid-sized Talarurus was unusual, being barrel-shaped and short-limbed.

First found in 1920s, Pinacosaurus has been the first armored dinosaur found in Asia, by the same expedition led by Roy Andrews that first found Velociraptor, Protoceratops, Oviraptor, an the latter's eggs. Pinacosaur remains found later in the 1950s were wrongly labeled "Syrmosaurus". In 1988, Pinacosaurus contributed to fuel the Dinosaur Renaissance even more, by giving a proof of social behavior among juvenile dinosaurs: several youngsters were found dead together in a small area, maybe buried in a sandstorm. This discover, made by a conjunct Chinese/Canadian expedition, also showed that ankylosaurians were not necessarily loners as traditionally thought.

Pinacosaurus has often appeared in speculative documentaries or mockumentaries about dinosaurs, even though usually unnamed — or at least, generically called "ankylosaur". Examples include Planet of Dinosaurs, "The Research of the Dragon", and more recently, The Truth About Killer Dinosaurs. The first two mention it because of the finding of the juveniles dead together: the third, more prosaically, to give a prey to Velociraptor, just like what classically happens to Protoceratops. Being the adult Pinacosaurus 15 ft long, far bigger than the 6 ft long Protoceratops, the programers chose a juvenile pinacosaur for the "raptor"'s meal.

  1. Entry Time: 2000s
  2. Trope Maker: Portrayals set in Cretaceous Mongolia (the Velociraptor 's land)

The original Stock Ankylosaur: Hylaeosaurus *

Huge Ankylosaurus has not always been THE ankylosaur. Was discovered at the beginning of the XX century, but several relatives were already known. They were simply smaller, less-armored, and above all, very fragmentary, and in the XIX were classified among the Stegosaurs. As a group, the Ankylosauria were recognized distinct only after Ankylosaurus. It's interesting thst one of the three inspirers of the name “dinosaur” was just an ankylosaur: Hylaeosaurus armatus ("armored lizard of the forest").

Discovered in England in 1840 by Gideon Mantell after his more famed dinosaur Iguanodon (and after Buckland's Megalosaurus as well), Hylaeosaurus was only 4 m long, less-than-half an Ankylosaurus (the size of Polacanthus above). In famous Crystal Palace Park in London made in 1852 by Benjamin W. Hawkings the Hylaeosaur shows up with the Megalosaur and Iguanodont, and depicted larger than was in Real Life. Unlike the other two "original stock dinosaurs", it has remained quadrupedal after 160 years of dino-history. But this doesn't mean it's more accurate at all: our Hylaeosaurus was sculpted like a giant, armor-less iguana.

Hylaeosaurus get usually mentioned together with its two companions when the "Crystal Palace" dinosaur sculptures are portrayed in media. In John Sibbick's famous Great Dinosaur Encyclopedia (published in year 1985) Hylaeosaurus is shown with a complex armor with sidewards-pointing spikes, and it is closerly-related with Polacanthus than to Ankylosaurus. Curiously the Polacanthus looks very different than Hylaeosaurus in the same book, showing a much simpler armor: this because the polacanth's "modern" look popularized by Walking With Dinosaurs emerged only in 1994, a decade later than Sibbick's work.

  1. Entry Time: 1854
  2. Trope Maker: the Crystal Palace Park in London

Other ankylosaurians

Sorry, these aren't here. If you're looking for , Nodosaurus, Edmontonia, Sauropelta, Saichania, and others, see here.

Armor-headed plant-eaters

The most recent group of ornithischian dinosaurs, marginocephalians have been usually discovered in Late Cretaceous terrains. They were closer to ornithopods (see further) than to thyreophorans (see previous), and are divided in two very different subgroups: ceratopsians and pachycephalosaurs, unified by their armored head.


The ceratopsians were a group of dinosaurs characterized by a bony "frill" at the back of the neck. Starting as small bipedal animals like all the main dinosaur groups, they evolved towards a heavy quadrupedal body plan, while lengthening the frill and growing horns on their eyebrows and nose. Even though ceratopsians had erect limbs like every other quadrupedal dinosaur, some portrayals have shown them with splayed frontal legs. Moreover, their legs tend to be shown stockier and more "elephantine" than in Real Life.

The ceratopsid family contains all the largest members of the group. Apart from the frill shape and number/length of the horns, ceratopsids shared the same basic look. They are classically divided in two subgroups: those with long frontal horns, short nasal horn and (usually) long frills; and those with short frill, no frontal horns, and (usually) a long nasal horn. Triceratops, Chasmosaurus, and Pentaceratops are member of the first subgroup, while Styracosaurus, Centrosaurus, and Pachyrhinosaurus belong to the second one. Finally, Protoceratops and Psittacosaurus have been the prototypical ancestral ceratopsians.

The T. rex's greatest rival?: Triceratops ***

Lived 68 to 66 million years ago in Late Cretaceous North America. It was one of the last discoveries from the Bone Wars: its original find, an isolated horn-core, was first believed to be from a bison. Its name means "three-horned face" and is due to its most prominent feature. It was about 26-29.5 ft/7.9-9 m long and weighing about 6-12 metric tons, and was one of the biggest ornithischian dinosaurs (only some hadrosaurs were larger). Hundreds of skulls are known so far, but (amazingly) not a complete skeleton. Two main species are recognized today: the larger Triceratops horridus and the smaller Triceratops prorsus, even though up to 15 species were described at one point due to the great variability of the skull.

Triceratops has traditionally been considered the largest ceratopsian; its size and abundance in the fossil record have contributed to making it the most popular one. It has always been beloved by dino-fans. Maybe because with its short tail, big head, and rhino-like body, it is the least reptilian-looking among the Stock Dinos (even in older depictions); or maybe, because of its historical reputation as "the only plant-eater able to defeat the Big Bad Tyrannosaurus rex" (even though ankylosaurs and maybe even the biggest hadrosaurs might also have been able to defeat the tyrannosaur in a fight).

Its portrayal in Jurassic Park consolidated Triceratops' popularity even more: the touching scene of the sick triceratops with the caring humans around has remained in public consciousness. And how could we forget the strong temper of Cera in The Land Before Time film?

Compared to other stock dinosaurs, Triceratops and its relatives have been portrayed fairly accurately. The ceratopsids in the original movie The Lost World (the Trope Maker, from year 1925) are nearly as realistic as those seen in the 1999 docu Walking with Dinosaurs, which are actually Torosaurus (though some research suggests that Torosaurus is just a more mature form of Triceratops, see below). Thanks to their obvious resemblance to rhinos, media Triceratopses have usually been portrayed as agile and active like a modern ungulate mammal; basically, the only mistake in older depictions (other than the aforementioned issue regarding the legs) is the wide lizard-like mouth without the typical ornithischian cheeks. For a brief period, it was considered that triceratops was covered in quill-like bristles (like their earlier relative Psittacosaurus, see below), citing what appeared to be broken off nubs in skin impressions of the animal's back. However, these are far more likely to be osteoderms (bony scutes), like those of an alligator. Nonetheless, portrayals of bristly ceratopsids have become common since then in paleo-illustrations.note 

Triceratops and T. rex have been shown fighting in modern works from the first dino-movies and through the whole paleoartistic tradition (including one especially iconic painting). In these battles, the percentages of victories between the tyrannosaur and the triceratops appears to about 50%. Though all this may even be Truth in Television, it's likely that the tyrannosaur preferred younger and more vulnerable prey than an adult Triceratops. Often considered the badass guy par excellence among plant-eating dinos, writers can’t resist the urge to make Triceratopses act like rhinos or even bulls. They’ll be ill-tempered, will charge everything, and may even moo like bovines.

The ceratopsids’ horn structure was more like cattle’s than to a rhino’s: that is, bony protrusions covered with a horny sheath. Their function is still debated: ceratopsian horns may have simply been display devices. The frequently-seen "Triceratops goring to death a big carnivore" scene might not be realistic, and some think the frontal horns were too fragile and not pointed enough to go through flesh. On the other hand, given the keratinous sheath would have made the horn less likely to break and helped better shape it, goring may still be plausible. Another classic hypothesis is that triceratopses locked their horns like deer in head-vs-head combats, based on possible "wounds" found in ceratopsian skulls. However, only some Triceratops specimens show curved frontal horns apt for that, others had straight horns. The frill was variable, too: some individuals had tubercles on its edges, while others had smooth shields. Generally, most media Triceratopses have tubercled frills.

The parrot-like jaws are rarely mentioned, to the point that some authors omit the shape from their models to make Triceratops more like a rhino or a bull. Some have gone even further, showing ceratopsians with sharp carnivorous teeth even in the tips of their jaws (especially common in some rubber toy collections). In Real Life, the ceratopsians' jaws were the strongest among all plant-eating dinosaurs, filled with sharp cutting teeth behind the parrot bill, but were arguably adapted to eat fibrous plants, not tear meat (or at least this was not the main function, see further). Some thought the powerful maxillary muscles were anchored to the frill, but this is not proven. Even less mentioned are the pair of bony knobs near the cheeks; they may have been for protecting the head furthermorely, or they may have been only for display.

  1. Entry Time: 1925
  2. Trope Maker: The Lost World (film)

A dinosaur with a crowned head: Styracosaurus **

Several genera of horned dinosaurs other than Triceratops existed in Late Cretaceous North America, but only some of them have made appearances in pop culture, and Styracosaurus is the only one to do so with regularity, sometimes as substitute for Triceratops, other times together with it. Being more spectacular but less common in the fossil record than other ceratopsids, this makes it the usual Rule of Cool example.

Styracosaurus lived in North America 75 million years ago, slightly earlier than Triceratops. It was discovered in 1913 during the second great North American "dino-rush". note  About half as long as a triceratops (only 18 ft/5.5 m, weighing nearly 3 tons), the styracosaur was actually even more rhino-like. It had much longer horn above the nose but only hints of horns above its eyes. It had a round, short frill, but with several pairs of long spikes protruding from the top in a rayed manner, and shorter protuberances on the anterior edge. This sort of Horned Hairdo incidentally makes its head resemble the Statue of Liberty. No other known dinosaur had such ornamentation: other relatives had one isolated pair of spikes at the most, for example Centrosaurus (see below). Styracosaurus and Centrosaurus had also shorter and stronger jaws than Triceratops. Some speculate they were more sociable than triceratopses and lived in more numerous herds.

Styracosaurus' frill spikes were not true horns as commonly said, but only an Up to Eleven version of those protuberances seen in almost all ceratopsid species. Even though the most common portrayal has six spikes, it seems most specimens had only four. But don’t rule out seeing styracosaurs with eight spikes or more in popular works, or even with no frill and the spikes protruding directly from the back of the neck.

Why did ceratopsids have the frill? The bony core has a pair of large holes that make it less heavy but also less useful as protection (Triceratops was almost the only ceratopsid that didn’t have those holes). The frill could have been raised for threat display. Another hypothesis is that it was a thermoregulating device (like Stegosaurus' plates, Triceratops' shield seems to have been rich in blood vessels). Maybe the frill was for making the several ceratopsid species more distinctive (like the hadrosaur crests, see further). It is also possible that frills show sexual dimorphism.

The styracosaur has appeared in several works since the first portrayal in 1933 (in The Son of Kong), and is also a common feature in toys and popular books. On the other hand, recent documentaries haven't represented it so frequently. Maybe because in Real Life Styracosaurus could not battle Tyrannosaurus rex as Triceratops did, but only smaller carnivores like Daspletosaurus.

  1. Entry Time: 1933
  2. Trope Maker: The Son of Kong

The first-found dinosaur eggs?: Protoceratops **

Protoceratops lived 75—71 million years ago in Late Cretaceous Asia, unlike the giant ceratopsids, which were mostly North American in distribution. It was around 6 ft/1.8 m in length and weighed no more than 400 lbs./180 kg. Protoceratopsids are generally smaller and more primitive than ceratopsids, and were once considered the ancestors of the latter group (hence the name, meaning "first horned face").

At first glance, Protoceratops resembled a miniaturized Triceratops — four-legged, with the same robust body, short tail, and unmistakeably ceratopsian head. However, it differed from ceratopsids mainly in having no true horns. Other differences include: a simpler frill lacking protuberances; bigger cheek-spikes; stronger parrot-jaws; and legs more adapted to running. The genders might have been sexually dimorphic (larger skulls with a nasal bump and a couple of upper "canine teeth" probably belonged to males).

First discovered in Mongolia in 1922, Protoceratops is one of the most abundant Asian dinosaurs in fossil record, with hundreds of specimens discovered so far — earning it the nickname "the sheep of the Cretaceous" (given the large numbers of animals found together, they probably lived in herds). Many juveniles have also been found, and its growth pattern is one of the best understood among dinosaurs. It was the most famous Asian dinosaur until Jurassic Park made Velociraptor famous. The discoverer of Protoceratops, Roy Chapman Andrews, note  attributed to it some elongated eggs which now are known to belong to Oviraptor. These were the very first dinosaurian eggs ever identified. The original crushed Oviraptor skull was found nearby (see "Oviraptor" above). A classic image in paleo-art is showing Protoceratops hatching its eggs and chasing or even trampling an egg-robbing Oviraptor. However, several nests complete with eggs were found later in Asia, which were actually laid by protoceratopses.

One especially spectacular find (from 1971) consists of a Protoceratops and a Velociraptor clutched together: they were probably fighting each other when they were buried by a sudden sandstorm or a collapsing sand dune. It still remains the best evidence of a "dinosaur battle" between an herbivore and a carnivore. The Protoceratops appears to be biting the Velociraptor with its parrot-jaws, while the "raptor" is holding the protoceratops' head with its forelimbs and has one of its sickle-claws near the herbivore's throat. The real cause of the battle is uncertain, however: probably the protoceratops was defending itself and/or its offspring from the carnivore. note 

Despite its scientific relevance, because of its relatively modest appearance Protoceratops is less portrayed in pop-media than Triceratops and Styracosaurus. Perhaps the most well-known protoceratops is B.J., that yellow guy seen in Barney & Friends. In the much more beloved book series Dinotopia, the talking dino-character who befriends humans is also a Protoceratops.

  1. Entry Time: 1940
  2. Trope Maker: Fantasia

The parrot-dinosaur: Psittacosaurus *

Together with Protoceratops, Psittacosaurus is by far the most important and well-known ceratopsid predecessor. At least, if you ask paleontologists and paleo-fans. Rule of Cool always wins in pop-culture, with small-sized dinosaurs usually with very few chances to get consideration by writers or film-makers - points minus when they are plant-eaters.

Digression closed, here we have many things to say about Psittacosaurus, definitively one of the most important dinosaurs. An Asian animal like Protoceratops it has classically been considered the most ancient ceratopsian ever (lived 100 million years ago, in the Early Cretaceous) and the forerunner of all the Late Cretaceous “neoceratopsians” (aka Proto+Horned). With its primitiveness, Psittacosaurus resembles anything but a Triceratops: small (6 ft long), slender, with only hints of horns and frill. Once thought to be capable of walking on all fours, detailed study of its forelimbs shows it was entirely bipedal. The main trait revealing its relationship with Triceratops is the parrot-like bill (the hallmark of all ceratopsians) which gives it the name “Psittacosaurus” (“psittacos” is Greek for parrot). Another thing which ties Psittacosaurus with its horned descendants are the prominent bony “cheeks”.

Psittacosaurus was discovered in the 1920s in Mongolia together with Protoceratops. Its discovered was famed paleontologist Roy Chapman Andrews – a very adventure-loving guy, to the point he could have even been the inspiration for Indiana Jones as said above. Since then, psittacosaurs have been discovered everywhere in eastern Asia, but recognized a basal ceratopsian only in the 1970s (it was believed an ornithopod before). Its fossil record is extremely rich, just the same level of Protoceratops - individuals from all ages are known, and also several nests full of eggs. Our “parrot-dinosaur” also detains the record of the non-avian dinosaur with most species described, more than 10!

In the 2000s, many new discoveries have furtherly raised its importance, making it perhaps the most scientifically well-known member in the whole dinosaur world. The main discovery has been made in Liaoning, where one specimen has preserved integument which shows porcupine-like quills raising upwards from its tail, for uncertain purpose (Defense? Mating?). These were the very first filamentous skin-structures ever found in an ornithischian dinosaur; this has changed our perception of bird-hipped dinosaurs, which might be more similar to birds than previously thought. Indeed, a few scientists now argue those quills (or similar structures) could also be in all the other more evolved ceratopsians, Triceratops included. Another unexpected discover made in year 2000 in the same site, did debunk the classic “Mesozoic mammals were underdogs ruled by dinos”: the cat-sized carnivorous mammal Repenomamus has been found with baby Psittacosaurus remains in its ribcage! In 2016, its scales were discovered to have preserved pigments in them, revealing it to be a countershaded dark brown on top and a lighter brown on the bottom, like a deer. This resulted in modelers building what many news sites bragged to be the most accurate non-avian dinosaur model of all time.

  1. Entry Time: 2000s
  2. Trope Maker: the fossil discoveries from that period

One and the same?: Torosaurus *

Torosaurus was mainly made famous by Walking with Dinosaurs in 1999, where is portrayed as the main ceratopsian in the show (Triceratops appear only in form of a carcass). But well before 1999 Torosaurus was already known among dino-enthusiasts because of its huge skull, long believed the biggest among every land-animal that ever existed — 8-9 ft long, taller than an adult person if put vertically. When its huge frill was automatically raised up by lowering the main head, the shield could have been used as a scaring device against predators and rivals, making the animal looking bigger that it actually was if seen from the front. According to some, the choice to give to Torosaurus the main role instead of Triceratops is just because of its bigger frill.

Torosaurus latus was described during the Bone Wars by Marsh as a distinct ceratopsid genus than Triceratops. It was basically identical to the latter, only with a much longer frill that reached the shoulders when put horizontally: this shield was smooth-edged and with the typical two openings hidden by skin in life. Proper Triceratops lacked these openings: indeed, "Torosaurus" means "open lizard" just because of this (and not "bull-lizard" as stated in many sources).note  Lived in the same places and epoch of Triceratops, the extreme Late Cretaceous North America, but its fossils have always been rarer the latter.

Recently, some scientists have speculated that Torosaurus may not have been its own species at all, but instead may have simply been the mature form of Triceratops. This, naturally, led to a number of ill-informed internet articles claiming that Triceratops was somehow invalid. However, thanks to how scientific names work (if two different names are given to a species, the first one is the one that stays valid), this is impossible; instead, the name Torosaurus would be retired and Triceratops would remain in use. However, there is still good reason to believe that Torosaurus is a valid species. Torosaurus fossils have been found in areas where Triceratops fossils have not, and at least one sub-adult Torosaurus specimen is known.

  1. Entry Time: 1999
  2. Trope Maker: Walking with Dinosaurs

The real Unicorns: Centrosaurus & "Monoclonius" *

If you think Triceratops was the ultimate rhino-dino, is only because you have never heard about Centrosaurus. Like Styracosaurus above, the latter had a look that literally resembled a rhinoceros. Its nasal horn was much longer compared to Triceratops, and maybe was used in the same way of a modern black rhino - for obvious reasons, this cannot be verified. While the usual frontal horns were mere hints on Centrosaurus, renforcing even more the rhino-resemblance. About the frill, it was rather short, undulating-edged, with that pair of bony openings (covered with skin in the living animal), present in every ceratopsian outside Triceratops. The most unexpected thing is a pair of bony “hooks” curving downwards from the top of the shield; for some unexplicable reason, they are often taken out in Centrosaurus models or drawings.

Named in the beginning of the XX century, most of its remains were then attributed to another relative, “Monoclonius”, which has long been the archetypical “unicorn-dinosaur” in books and documentaries. Then, a spectacular find was made in Alberta in year 1980: a whole graveyard of about 500 Centrosauruses died together, probably killed while trying to cross a river in flood. This discovery was one of the first concrete evidence of migrating behaviour in dinosaurs, a bit like modern caribous and wildebeest (which also sometimes die in group during their river-crossings). Since then, Centrosaurus has replaced “Monoclonius” in books/docus as “the one-horned ceratopsid”. Curiously, the centrosaur was unnecessarily renamed "Eucentrosaurus" in year 1988, but returned Centrosaurus again soon after.

About “Monoclonius”, this one has been a very early discover, made in the XIX century during the Bone-Wars, but now is regarded by many as the juvenile-stage of Centrosaurus and its relatives. If so, then “Centrosaurus” would become invalid, because "Monoclonius" was the first name created. Two of the most familiar ceratopsid names, Torosaurus and Centrosaurus, risk now to get the same former fate of “Brontosaurus”.

"Monoclonius" (which doesn't mean "one horn" as sometimes said, but "one sprout") was slightly smaller than Centrosaurus but with the same rhinoceros-like appearence (long nose-horn and no real front-horns), and its frill had not the famous downwarding "hooks" of Centrosaurus (or it had them much shorter). While Triceratops was officially described by Marsh, "Monoclonius" was one of the few prominent bone-war dinosaurs first-described by Cope. Unlike alot of other "stock obscure" dinosaurs, Monoclonius has a notable and relatively recent appearance in popular culture: Prehistoric Beast by Phil Tippett, who would go on to be a supervisor and consultant for the Jurassic Park films.

  1. Entry Time: 1978 (Centrosaurus); 1984 (Monoclonius)
  2. Trope Maker: Planet of the Dinosaurs (Centrosaurus); Prehistoric Beast (Monoclonius)

Triangle-Shield: Chasmosaurus *

Maths are not always a exclusively-nerd thing. It can also be amusing, expecially when you can apply it to dinosaurs. Chasmosaurus can just be recognized by the geometry of its frill: strikingly angular in shape, if seen frontally almost seemed a reversed Isosceles Triangle with the base on the top and the apex attached to the skull. Its edge was also complex: smooth and V-shaped at the “hypothenusa”, spiky on the two upper corners, and half-smooth / half-undulating on the two “cathetes”. Moreover, this frill was also extremely elongated, almost like the Torosaurus one, and was arguably used for the same purpose.

The remaining head was far less spectacular: the horns were three like Triceratops, but were rather short in comparison – some individuals had mere hints of the frontal ones; we’re not sure if they’re from females or distinct species.

Known since the 1910s, Chasmosaurus is one of the most common ceratopsids in fossil record, and is often considered the prototype of the (usually) long-shielded subgroup: the Chasmosaurines (or Ceratopsines), which includes also Triceratops. However, the genus Chasmosaurus has been recently split in several new genera (year 2010). In Fictionland, the chasmosaur was portrayed in a bunch of old movies, and some modern-cartoon "Triceratops" have a suspiciously Chasmosaurus-like triangular frill.

  1. Entry Time: 1970
  2. Trope Maker: When Dinosaurs Ruled the Earth

Five horns...or not?: Pentaceratops *

Despite many of the most well-known ceratopsian genuses had the usual “saurus” ending (Torosaurus, Styracosaurus, Centrosaurus, Pachyrhinosaurus, Chasmosaurus), most described kinds have the same suffix of the Great-Stock member. -ceratopses do abund here: after Triceratops (“three horned face”) and Protoceratops (“first horned face”), the most well-known is Pentaceratops (“five-horned face”).

But did it really had five horns? Well… no. They were only three. The other two “horns” actually were simple protrusions arising from each cheekbone - a common ceratopsian trait, but particularly evident in Pentaceratops. One of the classic long-frilled ceratopsids, Pentaceratops looked pratically like the intermediate form between Torosaurus and Chasmosaurus: smaller than Torosaurus but bigger than Chasmosaurus, lived before the former but after the latter. Its horns were shorter than Torosaurus but more developed than many Chasmosauruses. Its frill was neither elliptical / smooth like the Toro’s one, nor triangular / complex like the Chasmo’s: it was rectangular and lightly serrated around its whole perimeter.

Known since the first half of the XX century from remains discovered in Texas, Pentaceratops gained more attention in the 1990s after the discovery of a gigantic skull which was attributed to its genus. Before that, Torosaurus, with its 2.5 m long skull, used to bear the record for “the biggest-headed land animal ever”; this putative pentaceratops’ skull was 3 m long. Science Has Marched On however, and this specimen has been deemed a separate animal in January 2011, meaningfully-named Titanoceratops.

  1. Entry Time: late 1990s
  2. Trope Maker: its alleged humongous skull

Thick-Nose: Pachyrhinosaurus *

Ceratopsids are classically known as “horned dinosaurs”: but this one seems not to have liked our definition. Pachyrhinosaurus (“thick-nosed lizard”), at a first glance, resembles more an oversized Protoceratops than a Triceratops: it has no true horns on its skull, it had a thickened boss upon its nose, sometimes described as similar to a lunar crater. To compensate, its short frill has an elaborate shape, with two horn-like spikes protruding from its rear-corners, other minor undulations elsewhere, and a small prominence pointing upwards from the center of the shield.

It’s worth noting, however, that juvenile pachyrhinosaurs did have a typical ceratopsid nose horn that was absorbed into the skull as they grew. This detail, along with its great size, massive limbs and other elements, firmly demonstrates that it is a true ceratopsid, more precisely a Centrosaurine - that is, a relative of Centrosaurus and Styracosaurus. As a matter of fact, Pachyrhinosaurus was the largest and the last surviving Centrosaurine, living at the same time as T. rex and Triceratops (though much farther north).

Before the nineties Pachyrhinosaurus was one of the rarest ceratopsids: then, in the 1990s, a whole herd was discovered in Alaska. Since other Pachyrhinosaurus remains have been found much souther, this might be another proof of migrating behavior among horned dinosaurs. Pachyrhinosaurus should never get confounded with Pachycephalosaurus (see further): both had something “thick” in their skull, but in the latter’s case was the head.

The Turn of the Millennium saw an increase in Pachyrhinosaurus's appearances in pop culture, particularly as a background character in Dinosaur, as a major character in the eighth Land Before Time film, and in a starring role of the Walking with Dinosaurs film.

  1. Entry Time: 2000
  2. Trope Maker: Dinosaur

Other ceratopsians

Sorry, these aren't here. If you're looking for Anchiceratops, Avaceratops, Leptoceratops, Zuniceratops, and others, see here. Or here.


Unlike ceratopsians, pachycephalosaurians kept the original bipedal body plan, but evolved thick skull roofs and bony knobs on their heads for uncertain purpose. Like ceratopsians, there is the possibility that were omnivores. Needless to say, the iconic member of the group is also the biggest one, Pachycephalosaurus.

My Brain is Big: Pachycephalosaurus **

Lived during the Late Cretaceous 70-66 million years ago in North America like many well-known dinosaurs. It usually shows up when an author feels like showing an "exotic" dinosaur. Its relationship with other dinosaurs has long been uncertain: originally classified as an ornithopod note , its affinity with ceratopsians was demonstrated only in the 1980s.

Pachycephalosaurusnote  ("thick-headed lizard") is by far the biggest known pachycephalosaur. Its actual length is uncertain: popular books often set its size at up to 30 ft/9 m; a length of 15-18 ft/4.6-5.5 m is more likely (the other relatives were not longer than 10 ft). Described in 1931 from a single skull, it was initially identified as Troodonnote , and renamed Pachycephalosaurus only in 1943. No other parts of the body have been found since then: reconstructions are typically based on a smaller, less-famous pachycephalosaurian, Stegoceras (see below).

Pachycephalosaurus is distinguished by its dome-like head which makes it look very intelligent. However, the height of the dome was almost entirely made of almost one-foot-thick bone, and its brain wasn't larger than other dinosaurs'. Its nickname "The Bone-headed Dino" is quite accurate. A number of bony knobs and blunt spikes around the base of the dome and on its nose contrasted with the smoothness of the dome to create a look of partial baldness or of a monk's tonsurenote ; hence the epithet "Friar Tuck-osaurus" in The Lost World: Jurassic Park film.

Being totally bipedal, pachycephalosaurians were superficially similar to theropods, but their jaws and grinding posterior teeth were typically ornithischian (and thus plant-eating). However, Pachycephalosaurus had weaker jaws than ceratopsians or hadrosaurs and still retained small pointed teeth on the tips of its jaws which were lost in the more evolved bird-hipped dinosaurs; this would indicate the pachy had a mixed diet based on plant material with insects and small vertebrates as a supplement. Its relative Stegoceras shows small five-fingered forelimbs, a slender body, long tail, and running legs (perhaps less adapted to running than those of the similar-shaped "gazelle-dinosaur" Hypsilophodon). The body of Pachycephalosaurus probably was similar to Stegoceras, but the former being larger than the latter, its body might have had an overall stockier frame.

As one of the most recent groups of herbivores/omnivores in formal dinosaur classification, pachys never appear in the oldest works. The ur-example was the 1956 novel A Gun for a Dinosaur; one of the most popular ones was The Land Before Time in 1988, where the pachy shows up as a predatory villain trying to kill one of the protagonists with headbutts. The headbutting is a standard trait when pachycephalosaurs appear in works. Classic dino-books and documentaries from the Dinosaur Renaissance traditionally depicted males trying to impress females by ramming their heads into each other. note  However, scientists found in the 2000s that the smooth domes would have slipped if struck against each other, and proposed that pachycephalosaurians bashed each others' sides and hips instead. But even this has been disputed: recent studies seem to show their necks were weaker than traditionally thought, maybe not able to withstand such an impact. Now many scientists think pachycephalosaurs simply used their dome heads to display maturity like an oversized toucan bill. Even more recently, a 2013 study found healed injuries in multiple pachycephalosaur domes, suggesting that they were used for headbutting and/or flankbutting after all. The pachycephalosaurs' real lifestyle and diet will probably remain a mystery until more complete remains will be found.

The large Pachycephalosaurus was once the only bonehead portrayed in fiction. This changed in the 2000s when two smaller relatives, Stygimoloch spinifer and Dracorex hogwartsia (the latter discovered as recently as 2006) started making occasional appearances as well, thanks to their even spikier heads. A very recent theory (2009) suggests that these two horned pachys were just juvenile Pachycephalosaurus; if so, the latter will remain the only pop-cultural bonehead.

  1. Entry Time: 1956
  2. Trope Maker: A Gun for a Dinosaur (novel)

The other Stego: Stegoceras *

Rule of Cool is a merciless thing. It doesn’t matter if you are the most abundant, complete, well-known, or even the first discovered dinosaur within your group: if you aren’t cool enough, another cooler relative will take you the stock-role in pop-consciousness.

Stegoceras matches perfectly all this. By far the most abundant, complete, well-known, and even the first discovered dinosaur within its group, which should be renamed Stegocerates rather than Pachycephalosaurs. 2.5 m long, Stegoceras was just half the length of Pachycephalosaurus, but shared the same Friar-Tuckish face, having a smooth dome bordered by a collar of tubercles. But its dome was less-prominent, “only” 1 inch thick, and its nose lacked those spikes Pachycephalosaurus had. In short, it appears like the milder version of Pachycephalosaurus.

Both pachys lived in Late Cretaceous North America, but the smaller one was slightly earlier, as usual among Late Cretaceous dinosaurs. Was discovered in year 1924, but originally thought a weird ornithopod; the placement in the current group was made just after the discover of Pachycephalosaurus twenty years later. And don’t confound it with Stegosaurus, please. As a pachy, “the other Stego” was a small, two-legged animal with a heavy head and the “body armor” limited to its skull.

The other stego has also the distinction to be the only pachycephalosaur from which many individuals are known, not just one or two, and the only whose body-frame is known with sureness, to the point to be used as a model for other relatives: when you watch the body, legs, arms, neck and tail of a pachycephalosaur, you’re arguably watching those of Stegoceras. In dinosaur books, the other stego is often treated as the effective stock pachycephalosaur, unlike TV programs which will ever prefer the namesake of the family. For infos about its possible lifestyle, see Pachycephalosaurus above.

  1. Entry Time: 1956
  2. Trope Maker: A Gun for a Dinosaur (as the model for the "Pachycephalosaurus" body)

Spiky Pachys: Stygimoloch & Dracorex *

Two North-American pachycephalosaurians have gained quite striking names: Stygimoloch spinifer and Dracorex hogwartsia. The former means "Spiky Devil from the Death River", the latter "Hogwarts' Dragon King".

Both lived in USA alongside Pachycephalosaurus and, surprisingly, are known only from one skull or little more. Stygimoloch was discovered in the eighties: Stegoceras-sized, was the only known pachycephalosaur with spikes developed into true horns, and its dome was tall and narrow (one former invalid synonym of it was "Stenotholus", "narrow head"). Meanwhile, Dracorex was found only in 2006: also of similar size, had an almost-as-spiky skull coupled this time with a flat head. Even though much more developed, the spiky ornamentation of both was very similar to Pachycephalosaurus. Basing on this detail, some have proposed in the 2000s that the “devil” and the “dragon” are just different immature stages of Pachycephalosaurus, with Dracorex being the most immature growth-stage, Stygimoloch the intermediate one, and Pachycephalosaurus the fully-mature form.

Stygimoloch recently had a memorable scene in Jurassic World: Fallen Kingdom; it's worthy to be noted that film consultant Jack Horner advised against featuring the Stygimoloch due to the above controversy, but was overruled by the filmmakers. Talking about Dracorex hogwartsia, our "harrypottersaur" is one of the few real dinosaurs portrayed in the TV series Primeval, even though in a quite fanciful way, with an actual dragon-like crest on its back.

  1. Entry Time: The 2000s
  2. Trope Maker: Disney's Dinosaur (Stygimoloch); Primeval (Dracorex)

Other pachycephalosaurians

Sorry, these aren't here. If you're looking for Homalocephale, Prenocephale, and others, see here.

Bipedal plant-eaters (usually)

The Ornithopod group contains several ornithischian dinosaurs of different size, from Middle Jurassic to Late Cretaceous. The smallest ones were slender and completely bipedal, and probably omnivorous. The more evolved ones became bigger and returned to a partial quadrupedality, as well as becoming strict herbivores. The largest were among the most massive non-sauropod dinosaurs. "Ornithopod" means "bird-foot": they had limbs and feet similar to but (ironically) less bird-like than those of theropods. Unlike the latter, they had small mouth openings and blunt teeth for grinding plant matter. Ornithopods are the most abundant dinosaurs in fossil record; even though they lacked the thick defenses of the ornithischians mentioned above, they made up for that with either speed or sheer bulk.


Hadrosaurs are nicknamed "duck-billed dinosaurs" because of their wide, flat beaks especially evident in some species, less so in others. They all lived at the end of the Cretaceous. The biggest and most evolved ornithopods, their grinding maxillary mechanism was the most efficient of all reptiles ever, and they also developed complex prominences above their skulls with social functions.

An unusually high number of hadrosaur species are portrayed in popular media, but these ones have received the greatest attention: Parasaurolophus and Corythosaurus thanks to their evident headgears; Edmontosaurus (called Trachodon or Anatosaurus in old media), because it's the most duck-billed duckbill, and one of the first described too; Maiasaura, which has heavily contributed to the Dinosaur Renaissance; and, more occasionally, Saurolophus, Kritosaurus, Hadrosaurus, and Lambeosaurus. Breaking the usual rule, none of them is the biggest known hadrosaur.note 

An instrument for trumpeting?: Parasaurolophus **

Lived 76 to 73 million years ago in Late Cretaceous North America. 25 ft/8 m long and weighing 4-5 metric tons (roughly as much as an elephant), Parasaurolophus was a typical hadrosaur, with longer and stronger hindlimbs than forelimbs, three-toed feet ending in blunt nails, a long powerful tail, a small "hump" on its shoulders, a flexible neck with many short vertebrae, and the classic "duck-billed" head (although the "bill" was not as flat and wide as other relatives). Its long, backwards-pointing protrusion made its skull a bit longer than a human’s height. Even though is often called a "horn", it was actually an extension of the nasal cavities, and ended in a blunt point. note  Its unique crest makes Parasaurolophus one of the most popular hadrosaurs (if the most popular). Significantly, Parasaurolophus' remains are rarer than other duckbills.

The hadrosaurs' lack of specific weapons has led to them being nicknamed "the Cretaceous antelopes". They are usually shown in dino-books and documentaries as "chosen preys" for tyrannosaurs, "raptors" and even giant crocodiles, incapable of offering resistence and obliged to flee away from them. This might be Truth in Television, but in Real Life "duckbills" were not exactly gazelle-like creatures. Adult hadrosaurs were strong and heavily-built: in a high-speed collision against a tyrannosaur, the hadrosaur had less of a chance of falling down (and would've been able to get up more easily thanks to its longer forefeet). It's easier to imagine tyrannosaurs hunted young hadrosaurs more often than adults.

Like the sauropods, hadrosaurs used to be associated with water in pre-Renaissance times. The early discovery of some mummified hadrosaurs whose skin on their hands was believed to be remnants of webbing made scientists believe they were semi-aquatic creatures with literally duck-like webbed hands. We know now this skin bound the fingers together into a single, toughened "hoof" apt for walking on dry soil. Also, when on land, hadrosaurs were once shown assuming the same upright posture of an old-fashioned theropod. After the Renaissance, scientists described hadrosaurs as terrestrial animals, similar to modern ungulates but capable of shifting from a quadrupedal to a bipedal posture. Needless to say, amphibious hadrosaurs with webbed hands and upright stance still appear in recent media (see The Land Before Time).

Even after it was established that hadrosaurs were mainly terrestrial, scientists still said they were more skilled swimmers than most other dinosaurs and used to flee in water to escape the (less able) giant theropods. Recent research seem to indicate hadrosaurs were not particuarly accomplished swimmers in respect to other dinosaurs, or even that tyrannosaurs were more able to move in water than the "duck-bills" — of course, this cannot be verified.

Specifically regarding Parasaurolophus, countless hypotheses have been made about the function of its "horn": among them, a tool to thread its way through the dense forest foliage, or even a snorkel when swimming underwater. The latter just plain doesn't work; there aren't any holes on its tip. The most commonly-accepted scientific theory is that the complex series of tubes found within were used for amplifying calls like a sound box of an instrument. Scientists have even turned out to reproduce these calls, which quite resemble a brass instrument. note  It's highly probable the headgear had also a display function: it might have been brightly colored to attract attention, and could have had a flap of skin stretched from it to the neck, but both hypotheses are unproved.

This dinosaur has a rather strange destiny in fiction: it has appeared in almost every dino-film, but almost always in minor roles — basically with the sole purpose to increase the variety of the "dinosaur world". And don’t expect to hear its name, either — Even though not one of the shortest dino-names, it remains cool-sounding anyway. A good example is in the Jurassic Park films. Some Parasaurolophuses are visible behind the Brachiosaurus in the famous "Welcome to Jurassic Park!" scene of the 1st film; they are also seen in every following sequel, too. But all these were simple cameos, and the animal is never named. note  Other unnamed appearances are in Disney’s Fantasia and Disney's Dinosaur. One rare example of a major-character Parasaurolophus is seen in The Land Before Time... at least, Ducky and her parents are officially labeled as such: they’re actually another hadrosaur, Saurolophus (see below).

  1. Entry Time: 1940
  2. Trope Maker: Fantasia

Donald Duckosaur: the Edmontosaurus / Trachodon / Anatosaurus / Anatotitan case **

No other stock dinosaurs has had such a Mind Screw story than the Edmontosaurines (The Brontosaurus/Apatosaurus is nothing in comparison). Here, Science Marches On is to a Up to Eleven degree, coupled with a huge Taxonomic Term Confusion and I Have Many Names. Edmontosaurines roamed North America at the very end of the Cretaceous, 73-66 mya. Two genera were then recognized, Anatotitan and Edmontosaurus, but they were reunited into one in 2011. Some claim this makes Edmontosaurus the only valid name for this dinosaur, while others support the separation of Anatosaurus. By any name, these creatures included both normal-sized species (10 m) but also some of the biggest hadrosaurian species, reaching 12/13 m long — as long as T. rex and a bit heavier than it. Despite this, their size didn't preclude them to be among the rex's favorite prey. note .

Edmontosaurus (if it includes Anatosaurus) is one of the most scientifically known dinosaurs. More than 10,000 known specimens (most other dinosaurs have less than 100 known specimens, but usually much fewer) show every evidence about its life, even diseases. The most striking ones are the "petrified mummies," which have preserved not only skin prints, but also hardened muscles. If you don't believe us, see here. The second find is very recent, and shows an unexpected thing: hadrosaurs had a much more massive tail than traditionally thought. If this’d be true for all dinosaurs, then many classic studies about dinosaur biomechanics should be reviewed. For example, hadrosaurs and Iguanodon are often thought mainly quadrupedal, but a heavier tail would made their center of gravity just under their hips, perfectly balancing their body on two legs. Maybe hadrosaurs mainly walked on two feet and stayed on all fours only when grazing or resting, like kangaroos — a proof of this is that most hadrosaur and iguanodont tracks do not show prints of forelimbs.

Anatosaurus deserves the "duck-billed dinosaur" title more than any other hadrosaur, with its flat head and spatula-like beak. Edmontosaurus had a stockier head and a an undulating-edged upper bill, but was still more duckish than most relatives. Their Donald Duck-like face made these dinosaurs unusually nice-looking, making consequently ridiculous their possible portrayal in fiction as dragonlike monsters — resulting more similar to giant duck-lizards. In popular work, their "duckness" may even be strongly exaggerated, rendering its flat bill literally identical to a duck's, without any teeth or cheeks. In Real Life, hadrosaurs were not exactly toothless. Behind their bill they had up to a thousand teeth closely packed together in "batteries" and capable to grind the toughest vegetation (fossil pine needles have been found in the aforementioned mummies), making them the land-vertebrates with the highest number of teeth of every time.

Maybe they had a flap of inflatable skin on their nose to amplify their calls, but this is only a supposition. Traditionally Edmontosaurus and Anatosaurus have been considered the crest-less hadrosaurs par excellence, because their skull didn't show any bony prominence; but recently science marched on again and a specimen was discovered to have had a small, fleshy cockscomb on its head; this thing was discovered only thanks to the pietrified soft tissues found — maybe other "crestless" dinosaurs had some sort of fleshy protrusions on their head.

Here’s a brief summary of the edmontosaurines’ awesome taxonomic tangle. Their first remains, isolated teeth found in USA, were named Trachodon mirabilis ("admirable rough-tooth") in 1856 — among the very first dino-remains described in North America. During the following Bone Wars, two skeletons were discovered and named Trachodon copei. Soon later, two spectacular hadrosaur "mummies" (Claosaurus annectens) were popularly referred as the "Trachodon mummies." In 1917, a gigantic hadrosaur was discovered in Alberta near Edmonton, and named Edmontosaurus regalis. In year 1942, one scientist found that Trachodon must be only used for the original teeth, and coined a brand new name, Anatosaurus ("Duck lizard"), for both the Bone Wars skeletons (Anatosaurus copei) and the mummies (Anatosaurus annectens). Before the year 1990 two well-known genera were thus recognized, Edmontosaurus and Anatosaurus, and described as two distinct hadrosaurs in dino-books and documentaries. However, in that year, new studies showed A. copei being much more different than A. annectens and E. regalis put together, and scientists changed Anatosaurus annectens in Edmontosaurus annectens. At this point the copei was the only remained Anatosaurus, but... taxonomic rules say "Anatosaurus" should indicate only the annectens. This meant it should be renamed, too. Being scientists often very nostalgic, they decided to recall it with a similar name: Anatotitan ("giant duck"). And now Anatotitan should probably be sunk into Edmontosaurus, while Anatosaurus could return valid again.Quite simple, isn’t it?

Trachodon first appeared in pop-media in 1925 (The Lost World film adaptation), in which is portrayed as a prey for a giant carnivore. Since then, it became THE duckbill in public consciousness, to the point "trachodont" was also used as a popular synonym of "hadrosaur" (a bit like "brontosaur" as a synonym of sauropod). Since the "renaissance" times, Anatosaurus has become the most widely-used name. After 1990, Trachodon rapidly disappeared in pop-consciousness -– even though its ghost is still seen sometimes. As it seems, the name Edmontosaurus hasn’t gone a long way in non-docu media: when an edmontosaurine appears, is simply known as "duckbill," and the crested Parasaurolophus has become the most portrayed hadrosaur today. Compensating this, edmontosaurines remain still quite common in documentary media, being the only hadrosaurs which could have met Tyrannosaurus rex in Real Life (with the possible exception of the crested Hypacrosaurus, which lived from 75 to 67 million years ago). Current dino-books usually show them with the name Edmontosaurus, while "Anatotitan" became popularized by Walking with Dinosaurs, and has also appeared in Primeval. According to the most recent researches, its proper name is either Edmontosaurus or Anatosaurus.

  1. Entry Time: 1925
  2. Trope Maker: The Lost World (film)

The Good-Mother dinosaur: Maiasaura *

This hadrosaur deserves a special mention. The same size of Parasaurolophus Corythosaurus Saurolophus & Kritosaurus and contemporary to them, 74 mya, Maiasaura had not the striking headgear of the first two (only a small relief above the eyes), nor did it have such a wide bill like the edmontosaurines. Nonetheless, it has been one of the most important dino-finds ever.

Hundreds of Maiasauras were discovered together in Montana in year 1980 by famous paleontologist Jack Horner note , in what is known today as the "Egg Mountain.", at that time a small lake-island. His mountain showed not only adults, but also many fossilized, 6 ft wide, crater-like nests made of earth and full of hadrosaurian eggs, hatchlings of all ages, and even skeletons of embryos still inside the eggshells!

Before the 1980s only few dinosaurian eggs were known to science, and parental caring among dinosaurs was still a very speculative issue. Horner's discovery was a true snapshot of daily dino-life. He noted that the youngest specimens still had incomplete limb-bones: this meant they were incapable of leaving their nests. And yet, their teeth were noticeably worn, as they were already eating tough vegetation. How could they feed on themselves? Here is the proof of parental care: only adult maiasaurs could feed the young to make them surviving until they grew larger and finally could leave their nest alone. Horner gave a Meaningful Name to his caring dinosaur: Maiasaura means "good mother lizard" (note the unusual feminine suffix -saura). It was just his deep study about this dinosaur that has given to Horner his current prestige in the scientific community.

Horner and then other scientists made this possible reconstruction of Maiasaura lifestyle. Huge herds of possibly 10,000 individuals used to migrate across Western North America from the northern Canada south to Montana to winter in their island. Here, they mated, built their nests, laid their eggs, and filled their nests with decaying vegetation to keep the precious eggs warm: remains of fossilized rotting plant material have been found in these nests.note  After the hatching, adults feed their helpless babies with good food, moved by their cute appearance (the babies’ skulls show large eyes and short muzzles like modern mammal cubs). After having developed their skeleton, the youngsters started to search their food on their own; finally, the whole herd undertook again their migration toward the North, to pass here the Polar summer. In short, an overall behaviour very similar to many modern migrating birds.

This reconstruction made the top of the Dinosaur Renaissance, definitively debunking the old big, stupid, unfeeling, oafs thing, and making Maiasaura just as common in popular books as Parasaurolophus Corythosaurus & "Anatosaurus" since then. Some years after 1980, the discover became known among pop-writers, too. Only... Maiasauras inconspicuous appearance was not interesting enough. Even though the "good mother dinosaur" and the whole argument are widely mentioned in the 1st Jurassic Park novel (which, by the way, had Horner as the consultant), this was totally overlooked in Steven Spielberg's following film. Other Hollywoodians resolved the problem in another way: giving Maiasaura's behaviour to other relatives. In The Land Before Time, the hadrosaurs (actually, every herbivorous dinosaur) migrate through the lands and hatch their young in crater-like nests made of earth. This was copied later by Disney's Dinosaur (this time the duckbills were substituted by Iguanodon). All OK? Obviously, not. We have no proof if other dinosaurs really behaved the same. It's like saying that if sparrows build cup-like nests, then every other bird must build cup-like nests just because is a bird. Mind this: have you ever seen an ostrich or a penguin brooding their eggs in a cup-like nest built on a branch?

In The New '10s, Maiasaura makes its first notable film appearance in the Japanese animated movie You Are Umasou where it's shown to live up to the "Good Mother" in its name, taking in an orphaned Tyrannosaurus and lovingly raising it as its own along with its biological children.

  1. Entry Time: 1990
  2. Trope Maker: Jurassic Park (the first book)

My, what big crest you have!: Corythosaurus *

Hadrosaurs were very diversified in Real Life. Even though they shared the same body-plan, their head was wildly diverse. They are divided in two main lineages: basically, those with hollow crests, and those without. Other than Parasaurolophus, the only hollow-crested duckbill with a significant number of appearances in pop-media is Corythosaurus. Naturally, the latter has been a much rarer sight. In theJurassic Park film series Corythosaurus joins Parasaurolophus only in the third film. Just like Parasaurolophus, good luck if you'll ever hear Corythosaurus named in fictional media. Compensating this, it has been just as common as Parasaurolophus, Maiasaura, and Edmontosaurus in documentary works, which regularly show it with its distinctive crested look.

Corythosaurus was the same size of Parasaurolophus (8 m long), and lived in Late Cretaceous North America 77-76 mya. A classic error in paleo-art is to depict these two dinosaurs living alongside Tyrannosaurus rex. Since the "rex" was discovered in more recent terrains (68-65 mya), this makes a slight Anachronism Stew case. If the artist did the research these two hadrosaurs will interact with other smaller tyrannosaurids like Albertosaurus. First discovered in 1912 by Barnum Brown note , the "cory," unlike the "para," has one of the richest records among hadrosaurs. Several complete specimens known to science, including many juveniles.

The corythosaur’s cranial structure was similar to the parasaurolophus, with relatively narrow duckbill compared with "Anatosaurus" and expanded nasal bones which formed a crest. However, the Corythosaurus crest was very different than Parasaurolophus: it was laterally-flattened, round-shaped, and put upright above the head. It shape has often been compared to a Greek helmet (Corythosaurus just means "helmet lizard"), but some have (more prosaically) defined it as frisbee-like or dish-like. This crest was hollow like that of Parasaurolophus, but with less complex internal structure. It seems very different-sized and also different-shaped between genders and growth stages: adult males have the biggest, tallest and roundest ones, while those of females and youngsters were smaller and narrower, and the hatchlings were born devoid of it.

Issues regarding the possible functions of the corythosaur’s crest are like those regarding Parasaurolophus. Like Corythosaurus, female Parasaurolophus could have had shorter crests than males. Even though some skulls do show some variability, Parasaurolophus fossils are too rare to make a correct comparison — maybe the different-crested specimens are just different species within the genus. Since hadrosaurian crests are so differently-shaped, experts have concluded that they had also the function to distinguish visually the different hadrosaur species/genders/growth stages from each other, just like modern antelopes with their distinctive horns (let’s face it, comparisons with antelopes do work very well when talking about hadrosaurs). Moreover, the different-sized crests made differently-pitched sounds. As trombones emit lower notes than trumpets, adult males’ voices were lower than females, which in turn were lower than youngs. Then, as French horns and bassoons have a different timbre, so would have been for Corythosaurus and Parasaurolophus.

  1. Entry Time: 1940
  2. Trope Maker: Fantasia

USA and China make Peace: Saurolophus *

In general, Late Cretaceous dinosaurs are very similar in Western North-America and Eastern Asia. This because these landmasses were uned at the time by a stripe of dryland where today is the Bering Strait. This means that dinosaurs at the time could wander from one continent to another. Nonetheless, Asian and North American dinosaurs are usually classified as distinct genera (see Tyrannosaurus rex and Tarbosaurus bataar for example).

But there is also an exception: Saurolophus is perhaps the only dinosaur whose North American and Asian remains are always classified in the same genus, though to distinct species. First discovered in North America during the “Canadian dino-rush”, Saurolophus has left few fossils in Alberta, but much more have been then discovered near China during the Russian dinosaur-hunt in Mongolia in the 1950s (at the time Mongolia was under USSR influence) which followed the first American one led by Andrews in the 1920s. The Asian species, Saurolophus angustirostris, still remains today the most abundant duckbill from Asia.

However, its North American species (Saurolophus osborni) has also been important initially. Think about Parasaurolophus: discovered soon after Saurolophus, its name just means “near Saurolophus” or "almost Saurolophus". Indeed, both dinosaurs were superficially similar, with a bony “horn” pointing backward from the rear-end of their skull. But that of Saurolophus was far shorter, more pointed and horn-shaped, and was made by solid bone, not hollow like that of “Para”.

The two “horned” duckbills tend often to be confused each other by non-specialists - and their similar names don’t exactly help to resolve the mixup, too. The main example is seen in The Land Before Time: Ducky, the hadrosaurian member of the Five-Man Band of dinosaurs, has a clearly Saurolophus-like crest, and yet has been labeled Parasaurolophus. Astonishingly Saurolophus was closer to crestless hadrosaurs like Edmontosaurus than to Parasaurolophus! Just like Edmontosaurus, Saurolophus has often been depicted in paleo-art with a speculative, inflatable, frog-like air-sac on their snout, but this is not demostrated. This air-sac was conceived as a mean to amplify sounds just like the hollow crests of Corythosaurus & Parasaurolophus.

  1. Entry Time: 1988
  2. Trope Maker: The Land Before Time (identified as "Parasaurolophus")

The decayed Nobleman: Kritosaurus *

Most hadrosaurs have been described in Alberta at the beginning of the XX century, in the second memorable “Dino-Rush” led in North-America. Among them, one of the most historically relevant has been Kritosaurus.

In old books, it used to be shown as one of the prototypical hadrosaurs, along with “Anatosaurus”, Parasaurolophus, Corythosaurus, and Saurolophus, and their skulls were often shown together making a sorta Five Hadro Band. This “band” has also appeared once in cinema: in 1940, the “Rite of Spring” of Fantasia portrayed all but one member, but the missing one was Saurolophus, not Kritosaurus. More precisely, the kritosaur is the one with the bulged-nose: this sort of Roman-nose has often been cited as the origin of its name, “noble lizard” (though the real meaning of “krito” is uncertain).

Then, Science Marches On hit hard our Kritosaurus. Recent studies made since the 1990s showed that its first skull with the classic bulge actually pertained to another duckbill, the much more obscure Gryposaurus. To worsen things, Kritosaurus has revealed to be a wastebasket-taxon, and most of its former remains are now of uncertain attribution. Today, we even don’t know if it had really the classic bump on its nose, and “Kritosaurus” has now become a poorly-known genus just like Hadrosaurus.

  1. Entry Time: 1940
  2. Trope Maker: Fantasia

The first-known U.S. dinosaur: Hadrosaurus *

Surprise: “hadrosaur” not only means one precise group of related dinosaurs, it also indicates a single genus of duckbill: Hadrosaurus. But its importance is almost-entirely historical.

The very first dinosaur ever identified as such in America (and outside Europe) from more remains than simple isolated teeth, as early as in year 1858, like most early discoveries Hadrosaurus has a generic-meaning name, “heavy lizard”; and, oddly for an US dinosaur, was found in New Jersey – since dino-discovers in Eagle Land began in the East Coast while the upcoming “Bone-Wars” were “fought” in the West, one could say about a veritable Dino-Rush. Hadrosaurus foulkii (William Foulke was its first discoverer) was already recognized as an Iguanodon relative, but the latter was still depicted as totally-quadrupedal at the time. Hadrosaurus remains, though very incomplete, cleary showed an at least partly bipedal creature. Joseph Leidy (its namer) was the first paleontologist to have described a large-sized dinosaur in the classic upright posture: a revolutionary idea at the time, which became more popular later, expecially after the countless portraits of another guy, guess who.

Hadrosaurus has also the distinction to have been the first dinosaur ever mounted in a museum; however, the original bipedal posture has changed from upright to horizontal since the 1970s. Sadly, Hadrosaurus skull was pratically unknown, so Leidy didn’t understand to be in front of “the first duckbill discovered”. Despite this, some books have portrayed Hadrosaurus with a bump-nosed head for some reason, like what has happened to Kritosaurus. Actually, Hadrosaurus is so incomplete that it could be a synonym of another kind of hadrosaur, though a recent study seems not to agree.

Hadrosaurus was the animal originally chosen by Michael Crichton for the "stampede scene" in his Jurassic Park first novel, while Spielberg's following film chose to substitute it with the ornithomimosaur Gallimimus. Sometimes Hadrosaurus is confused with Edmontosaurus in popular non-fictional representations.

  1. Entry Time: 1990
  2. Trope Maker: The Jurassic Park novel

The biggest duckbill?: Lambeosaurus *

Even though is often passed off, hadrosaurs were the biggest plant-eating non-sauropodian dinosaurs. The most massive species were taller, longer and heavier than even the larger ceratopsians, stegosaurs, or ankylosaurs. And though not necessarily taller/longer, thanks to their massive bodies, they were heavier than giant theropods like Tyrannosaurus and maybe even Spinosaurus itself! But which kind was the record-holder?

Traditionally, two hadrosaurs have contended the record: North-American Lambeosaurus and Chinese Shantungosaurus. Lambeosaurus ("Lawrence Lambe's lizard"), one of the most striking-looking hadrosaurs, has also a rich fossil record, with two distinct species described plus a putative third one (reclassified in 2012 in a brand new genus, Magnapaulia). Lambeosaurus has also given its name to one of the two main hadrosaurian subgroups, Lambeosaurines aka hollow-crested duckbills (the other subgroup is called Hadrosaurines or Saurolophines): Parasaurolophus and Corythosaurus are, thus, lambeosaurines.

Overall, Lambeosaurus was similar to Corythosaurus with a flat, vertical crest with the same hollow spaces. However, the crest of the most known species (Lambeosaurus lambei) was taller, narrower, more rectangular, and with a secondary point raising backwards: a sort of “glove” with the “thumb” placed at 90° in respect to the main body (it is possible though, that only males did have that secondary point). The other confirmed species (Lambeosaurus magnicristatus, "big-crested Lambe's lizard") had a more rounded crest without the secondary point, but was spectacularly big and pointed slighty forwards.

Magnapaulia laticaudus (former "Lambeosaurus laticaudus"), even though poorly-known with no known skulls, has the distinction to be the biggest North American hadrosaur known so far: 15m/50ft of length and perhaps 12 tons of weight, twice the weight of a Tyrannosaurus rex. While the two confirmed species were “only” 10 m long and weighing 4/5 tons, the same size as most hadrosaurs. Significantly, the normal-sized Lambeosauruses have classically been oversized in books, to match Magnapaulia.

  1. Entry Time: 2001
  2. Trope Maker: The Land Before Time films

Other hadrosaurs

Sorry, these ones aren't here. If you're looking for Hypacrosaurus, Gryposaurus, Shantungosaurus, Tsintaosaurus, and others, see here.

    Hadrosaur predecessors 

There were many non-hadrosaur ornithopods as well, but only one of them has made significant appearances in fiction, Iguanodon (again, this is the biggest of the ensemble). If you are lucky the much smaller Hypsilophodon may also show up, but it's almost never named. And if you're really lucky you might see Camptosaurus and Dryosaurus. Here we'll mention also Tenontosaurus and Ouranosaurus because both are strongly-associated with one famous predatory dinosaur each.

The Veteran of the dinosaurs: Iguanodon **

Living 126 to 125 million years ago in Early Cretaceous Europe, this is the most iconic non-avian dinosaur from the "old continent." It’s also one of the most scientifically well-known dinosaurs, and one of the most abundant in fossil record. Iguanodon has had a special role within the stock dino-ensemble. Along with Megalosaurus, it’s the only dinosaur that has covered the whole history of scientific and popular portraits, but unlike the megalosaur, has managed to preserve its fame still today.

Although nearly as big as Tyrannosaurus (10 m or more, and up to 4 tons), Iguanodon has not an expecially striking look among stock dinosaurs. Being an earlier relative of hadrosaurs (and possibly their ancestor), its shape resembled one of the latter, with three-toed hindfeet, flexible neck (but less so than hadrosaurs), long tail stiffened by bony tendons, massive body, hindlimbs much longer and stronger than forelimbs. Non-hadrosaurian traits include: the backbone not curved at the shoulder level; grinding teeth much less numerous and put in one single row on each half-jaw; a totally crest-less head; a deep, narrow beak very unlike the duck-billed one.

The hands of Iguanodon contain all the "oddities" in its skeleton. The most known is the spike on its hand made of the first digit's phalanxes fused together and encapsulated in a horny sheath, usually shown in books as a weapon against enemies. And it had an opposable "pinkie" finger, maybe to grasp vegetation. Like hadrosaurs, the three central digits were fused together in a hoof-like structure and supported the weight of the dinosaur when on four legs (though incorrect freely-fingered iguanodonts-hadrosaurs often appear in portraits). We don’t know for sure if iguanodonts and hadrosaurs were mainly tree-browsers or ground-grazers. However, classic portaits usually show iguanodonts in the usual "tripodal" stance and browsing like a giraffe. Several paleo-works have also added a long extendable giraffe-like tongue to reach tree-foliage, but this is unlikely.

Iguanodon is one of the three animals along with Megalosaurus and the ankylosaurian Hylaeosaurus which were called "dinosaurs" for the first time in history (1842), by the English paleontologist Richard Owen. Iguanodon was already identified in 1825, just one year after Megalosaurus, by English doctor and fossil-collector Gideon Mantell (it's the second non-bird dinosaur to have received a official name). It was initially described from its iguana-like teeth and few other incomplete remains: hence its name meaning iguana's tooth. But then, in 1877 about 40 Iguanodon skeletons were discovered within a coalmine in Belgium near the town of Bernissart, the very first "dino graveyard" ever found. Many other remains were later assigned to Iguanodon (often found outside Europe), but many have recently split in other genera (see Prehistoric Life).

Most dinosaurs have changed their look at least once: Iguanodon has done this twice. The first attempt of reconstrution showed a huge dragon-like quadruped, and one of its thumbspikes was inaccurately put on its nose—this is justified by the very fragmentary nature of its original remains. note  After the discover of the complete skeletons from the "dinosaur mine" in the 1870s, the iguanodon became bipedal and upright, but still reptile-looking, often shown with iguana-spikes running along its back, and with an overall theropod appearance. Finally, studies started in the 1970 and led by English paleontologist David Norman made Iguanodon returning quadrupedal again (though still capable to stay and run on two legs), and with cheeks hiddening the teeth in the living animal. note  An excellent example of this new portrait is seen in Disney's Dinosaur, which made Iguanodon the main character in the story — exaggerating its horse-like look with fleshy lips instead of the proper bill, and showing it running always on all fours like an actual horse.

Even though has been extremely common in dino-books and other non-fictional media, Iguanodon has not made significative apparitions in cinema or TV before Disney's Dinosaur and Walking with Dinosaurs were broadcast during the 20th-21st century change. Rule of Cool easily explains why: with its generic look and weak weapons, it don’t bear the comparison with Tyrannosaurus rex jaws, Triceratops horns, Stegosaurus plates, "raptor" claws, or the immense size of sauropods — and some portraits could even leave the beak or the thumbspikes, making it even more generic. However, its historical and scientifical importance won't ever be deleted in dino-fans' consciousness, as no other dinosaur has run the whole two centuries of popular portraits: from Crystal Palace rhinos, to giant two-legged iguanas, up to Disneyan horses.

  1. Entry Time: 1854
  2. Trope Maker: Crystal Palace Park

The dinosaur that went down the trees: Hypsilophodon *

When we think about small bipedal dinosaurs, our mind authomatically comes to guys like the “raptors”, the “compies”, or the ornithomimids. But there were also several ornithopods which shared an analogue body-shape with the latter; even though they are usually ignored by film-makers. The most iconic of them has always been Hypsilophodon.

One of the first dinosaurs discovered (middle XIX century), lived in Europe 130-125 million years ago together with its gigantic relative Iguanodon, and was originally considered the latter’s juvenile specimen. Unusually for such a small animal, dozens complete individuals have been found, and this also explains its historical role as the stock small ornithopod. Even though most remains come from England (especially the Isle of Wight), some uncertain remains come from North America. A very small dinosaur, 2 m long or less, the size of a dog, Hypsilophodon is easily distinguishable from theropods by its horny beak on the lower jaw, small mouth-opening typical of ornithischians, large grinding teeth at the bottom of the mouth hidden by cheeks in the living animal note , hands with five digits (coelurosaurs never have more than three fingers), and a more round belly to contain the typical large gut of a herbivore.

Hypsilophodon is nicknamed “the gazelle dinosaur”. The comparison works very well: it was a graceful, harmless, wide-eyed biped that escaped predators thanks to its agile legs well adapted for high-speed runs: it was certainly one of the fastest-running dinosaurs. If alive today, it would probably appear one of the cutest-looking dinos, maybe even suitable as a good household pet. But before the 1970s, Hypsilophodon used to be depicted as a tree-climbing animal, vaguely similar to a large, long-legged, spike-less iguana, and long depicted in this way in books, 3D models, and perhaps even fiction. Few other dinosaurs have had such a great Science Marches On change during their story. While Iguanodon was often reconstruted using a classical kangaroo as a model, Hypsilophodon was often compared with the "tree-kangaroo", a small kangaroo living in the canopy of the forests of New Guinea and northern Australia.

In the rare event this little critter is portrayed in the popular media, expect it to be portrayed as the dinosaurian Red Shirt, little more than a bite-sized snacklet for the big hungry carnivores. To compensate, Hypsilophodon has been quite common in paleo-art; for example, the portrayal made by John Sibbick in 1985 in the "Great Dinosaur Encyclopedia" depicted the animal with a green hide and eyes with cat-like pupils. Obviously we don't know if the hypsilophodont was really green and cat-eyed; however, this reconstruction has inspired several other further "hypsies" paleo-artistic depictions. As the picture was from the 1980s, the animal is shown scaly; today many scientists think it was covered by feather-like structures like other small ornithischians.

  1. Entry Time: 1988
  2. Trope Maker: The Land Before Time

The "wildebeest" of the Jurassic: Camptosaurus *

Let’s face it: it’s Rule of Cool that undisputedly dominates when coping with dinosaurs.

Camptosaurus is the perfect example. This is one of the most abundant dinosaurs in fossil record (with both young and adult specimens known), and also one of the most common dinosaurs in museums around the world: this abundance in museums is even referenced in the first Jurassic Park book, in which the boy Tim brings his father in a natural-science museum and shows him the first dinosaur skeleton they meet just belonging to a juvenile Camptosaurus. But when was the last time you’ve you watched it in recent documentaries other than Planet Dinosaur? The problem is, Camptosaurus lived in Late Jurassic North America just alongside dino-stars like these: Brontosaurus, Diplodocus, Brachiosaurus, Stegosaurus, and Allosaurus. Thus, it could have shown up in Walking with Dinosaurs, The Ballad of Big Al or even When Dinosaurs Roamed America. But, maybe, its rather generic appearance (by dinosaur standards of course) was judiced kinda incospicuous to capture the watchers’ interest.

Camptosaurus ("bent lizard") was similar to Iguanodon above, but smaller (5-7 m long) and with mere hints of thumbspikes — some portrayals show Camptosaurus totally spike-less or with fully-developed Iguanodon-like spikes, both incorrect. It had the same bulky body, horse-like head, and general shape of Iguanodon, but was probably more bipedal than the latter. It also preserved the ancestral forth digit in its feet, lost in the Iguanodon and the hadrosaurs: indeed, Camptosaurus was one of the most primitive large-sized ornithopods, and a possible ancestor of Iguanodon and, indirectly, duckbills.

In the Jurassic world still dominated by sauropods, camptosaurids and stegosaurians were the only big ornithischians which were successful, anticipating the great diversity bird-hipped dinosaurs reached later in the Cretaceous. The most known Camptosaurus species is Camptosaurus dispar; other alleged Camptosauruses found in Europe (Portugal and England) actually pertain to other genera.

  1. Entry Time: 2000s
  2. Trope Maker: Zoo Tycoon

The "gazelle" of the Jurassic: Dryosaurus *

The other well-known Late Jurassic ornithopod, Dryosaurus altus ("tall oak-lizard"), was even less-conspicuous than Camptosaurus, but has received a slightly better treatment showing up in all the three documentaries above, though with very minor roles — in one case, it serves only to give a prey to Allosaurus.

Dryosaurus was smaller than Camptosaurus and much more slender, similar to a Hypsilophodon in shape — being totally bipedal. Compared with Hypsilophodon, the dryosaur was larger (3-4 m long), slightly more robust, with a shorter head, toothless beak, and lacking the forth reversed toe of Hypsilophodon and (ironically) the closer-to-Iguanodon Camptosaurus. Like the camptosaur, Dryosaurus was a basal iguanodont, and the prototype of its own lineage, the Dryosaurids.

Both discovered during the Bone Wars, Camptosaurus and Dryosaurus have been found in the USA. Specimens once referred to Dryosaurus have also been discovered in Africa - more precisely in Tendaguru (together with Giraffatitan and Kentrosaurus); they have been recently re-classified as Dysalotosaurus.

Camptosaurus and Dryosaurus are very frequently portrayed in dinosaur books, especially the former; here both are typically shown as among the favorite preys of Allosaurus or Ceratosaurus, a concept that is almost certainly true. Indeed, in North American placements, camptosaurids and dryosaurids were respectively the “wildebeest” and the “Thompson’s gazelles” of their fauna, that escaped their reptilian “lions” and “hyenas” (allosaurs and ceratosaurs indeed) by running quick on two legs. Dryosaurids, being smaller and more manouvreable, were probably faster than camptosaurids, but the latter, being bigger and with a stronger physic, had more chances to defend themselves effectively against their predators. A fully-grown, 6 m long Camptosaurus was smaller than an Allosaurus but the same length of a Ceratosaurus (and heavier than the latter, 2 tons).

  1. Entry Time: 1999
  2. Trope Maker: Walking with Dinosaurs

Beware my long tail: Tenontosaurus *

One of the most iconic scenes in those paleo-artistic works made in full Dino-Renaissance was a fight between a whole pack of Deinonychus and a much heavier ornithopod. Even though Iguanodon was often chosen in this role, the most classic choice has been another relative, Tenontosaurus tilletti ("Tillett's tendon lizard").

This was one of the most basal known iguanodontians, an Early Cretaceous animal similar in size to the more evolved but earlier Camptosaurus from Jurassic. Unlike the latter, the tenontosaur was totally devoid of thumbspikes, and was once considered an overgrown "hypsilophodont" in older classifications - more precisely, the by far biggest member of the group. It had long frontlimbs (classic portrayals often show it quadrupedal) with five similar digits each, a long neck, a small head, and the primitive four-fingered feet of basal ornithopods, but its most distinctive trait was surely its tail: it was much longer than most other relatives, twice the length of the rest of its body, and often depicted as a sort of "whip" almost like the tail of a sauropod (but it could have actually been more rigid than often shown).

First found in the 1970s in Montana, its first skeleton was surrounded by several Deinonychus skeletons. It was just this detail that made John Ostrom to think about these predators as wolf-like pack-hunters capable to bring down giant preys with their agility and their sickle-claws; Tenontosaurus has thus given an indirect contribute to the public image of dinosaurs.

In these struggles, Tenontosaurus is usually shown swinging its enormous tail and hitting some “raptors” to death, before being killed and eaten by the remaining Deinonychus. The Tenontosaur-Deinonychus battle is more justified than the Iguanodon-Deinonychus one, both because the former has at least one possible proof, and because an adult Iguanodon would have weighed eighty times more than Deinonychus (see Raptor Attack). Some scientists, however, have recently suggested that the carnivores simply ate the carcass of the Tenontosaurus they found already dead. The presence of their skeletons around the herbivore could be explained if some “raptors” fought each other to the point that some ended killed by their own companions.

Maybe the first mention of Tenontosaurus in popular culture is in the first Jurassic Park novel: here the whole Deinonychus/Tenontosaurus thing is referenced, but Alan Grant attributes it to Velociraptor instead of to Deinonychus — perhaps the greatest proof that the latest one is the chosen raptor in the story.

  1. Entry Time: undetermined
  2. Trope Maker: portrayals involving Deinonychus

Duck-billed Spinosaur: Ouranosaurus *

Here’s one of the best dinosaurian Mix-and-Match Critter examples: Ouranosaurus ("brave monitor-lizard"). This medium sized (7 m/20 ft long) ornithopod looked like a cross between other more familiar dinosaurs. Flat duck-like bill like Edmontosaurus; a small relief on its head like Maiasaura; thumbspikes like Iguanodon; and, more strikingly, a wide spinal crest on its back, similar to Spinosaurus but less tall and extending from the shoulders down to the tip of the tail. Like the spinosaur, this dorsal crest has traditionally been depicted as a Dimetrodon-like "sail" in popular portraits. The duck-like bill is explained by the fact that Ouranosaurus was a strict hadrosaur relative, but still not one.

Discovered by a French expedition in Niger led by Philippe Taquet in the 1970s, Ouranosaurus nigeriensis (the only known species) was smaller than Iguanodon and lived in Cretaceous Sahara just like Spinosaurus aegyptiacus (which was found a bit more northernly, ex. in Egypt and Morocco). Some thought the two animals' dorsal crests were a common adaptation for an arid environment, acting as solar panels or radiators like what is often thought for the plates of Stegosaurus, but like the latter case this is unproven.

In popular works the spinosaur has often been shown as the predator of the ouranosaur, the latter being smaller and thus a potentially easy prey for it; but this is actually a mistake, simply because Ouranosaurus lived 15 million years before Spinosaurus (always in the Cretaceous, though). Just as an example, the Ouranosaurus one documentary appearance in Planet Dinosaur showed the two living at the same time.

Like Spinosaurus, today some scientists argue that Ouranosaurus had a fleshy hump instead of a “sail”, because its vertebrae are similar to those of modern bison. But others say that comparing dinosaurs with modern big mammals is not correct, since these are two completely distinct zoological groups. Until we don't found remains of soft tissues of both, the question will remain unanswered.

  1. Entry Time: undetermined
  2. Trope Maker: portrayals involving Spinosaurus

Other hadrosaur predecessors

Sorry, these ones aren't here. If you're looking for Altirhinus, Thescelosaurus, Rhabdodon, Othnielosaurus, and others, see here.

    Primitive plant-eating dinosaurs 

Among primitive ornithischians, Scelidosaurus Heterodontosaurus, and Lesothosaurus have traditionally been the most prominent.

Primitive tank-dinosaur: Scelidosaurus *

When we think about armor-bodied dinosaurs, our minds comes to stegosaurs and ankylosaurs. But let’s not forget Scelidosaurus: a very primitive thyreophoran from Early Jurassic, discovered in Europe and possibly North America (if the latter is true it could have met the famous double-crested carnivore Dilophosaurus in life)

Only 4 m long, half the length of an average Stegosaurus and small also for ankylosaurian standards, the scelidosaur was traditionally considered in the middle between stegosaurs and ankylosaurs, but some have recently suggested that it's the first true ankylosaur. Still, Scelidosaurus was more slender and far less armored than traditionally-indended ankylosaurs. Its armor was made only of small bony tubercles sparse in regular lines along its body and tail, while its small head had not a bony “cap” but just three short spikes on each rear-corner. Its jaws were typically ornithischian, but with the primitive frontal teeth on the upper one (like the pachycephalosaurs and Hypsilophodon, see above). Its limbs were robust but agile (Scelidosaurus means "arm lizard"), more similar in shape to bipedal ornithischians than to stegosaurs or ankylosaurs, note  and some scientists have hypothesized it was able to rear up on its hindlegs to reach higher vegetation, like the stegosaurs but unlike the proper ankylosaurs.

Scelidosaurus is a very early find among dinosaurs - its first skeleton is known since the XIX century even before Stegosaurus and Ankylosaurus have been known to science. Like most of the others earliest dino-discoveries, it was found in England. Having a not-so-impressive appearance Scelidosaurus has remained a little-stock animal. However, basal dinosaurs from Triassic and Early Jurassic often make paleontologists happier than their Late Jurassic or Cretaceous ones, because the most ancient dinosaurs help to understand a lot the affinities among the main dinosaurian groups, enhancing the reconstruction of their evolution.

  1. Entry Time: undetermined
  2. Trope Maker: Popular dinosaur books

Three kinds of teeth: Heterodontosaurus *

Among basal Ornithischian dinosaurs, there were also curious things. Heterodontosaurus, for example, might be renamed the boar-bird.

The "hetero" lived in Early Jurassic like Scelidosaurus but far souther, in South Africa, 190 million years ago. Heterodontosaurus superficially resembled the ornithopod Hypsilophodon with its slender, bipedal body, but was even smaller (1.20 m/4 ft long), more robust and with longer forelimbs. It was actually one of the "largest" basal ornithischians (not counting the scelidosaurids), despite being only a bit bigger than a Compsognathus. Its skeletons have not left tracks of feather-like structures around them, but since its close relative Tianyulong had surely them, it's highly probable that Heterodontosaurus also had them.

Unlike Scelidosaurus, Heterodontosaurus was discovered only in the Sixties. Its name means “lizard with different teeth”, and with reason: no other dinosaur had such a diversified dentition, with three kinds of teeth surprisingly similar to those found in mammals. The most noticeable are two pairs of canine-like “fangs” visible when the mouth closed; behind, molar-like teeth to grind up tough vegetation; in front of them the small peg-like teeth only on the tip of the upper jaw, the typical condition of all basal bird-hipped dinos.

We are not sure about what the heterodontosaur ate in life, because of this specialized dentition. The dominant hypothesis is thatHeterodontosaurus was a mostly herbivorous omnivore, eating insects other than vegetation, while the "fangs" could have been used not for alimentation but for display and/or competiton, a bit like in baboons (thus acting more like "tusks"). Some scientists suspect only males did have the large canines, but there is no evidence. Other heterodontosaurids had different combinations of teeth: some species were devoid of "tusks", others had them only in their upper jaw, and still others had them only in the lower jaw.

Heterodontosaurus has been a very common sight in popular informative dino-books as an example of an early basal ornithischian dinosaur, often preferred to other Triassic/Early Jurassic bird-hipped dinosaurs because of its unusual, striking look. In these portrayals Heterodontosaurus is often shown together with the two most-known early dinosaurs, Plateosaurus and Coelophysis, and sometimes shown as the latter's prey. This could be accurate, as prosauropods and Coelophysis-relatives did live along it in southern Early Jurassic Africa at the time...but Anachronism Stew and Misplaced Wildlife are in play altogether, since Coelophysis (as commonly-intended) lived only in Late Triassic North America, while the plateosaur was around in Late Triassic Europe.

  1. Entry Time: undetermined
  2. Trope Maker: Popular dinosaur books

Size doesn't matter (just for once): Lesothosaurus *

When talking about Ornithischians, we can find the same issues of Saurischians: in the Triassic/Early Jurassic they were all so-similar each other, it’s hard task to classify them accurately. Nonetheless, they are extremely important animals for scientists, no matter their often tiny size.

Other than the scelidosaurians and the heterodontosaurians (which make two distinct groups on their own), we have several other examples, among them Lesothosaurus, Eocursor, and Pisanosaurus. Lesothosaurus diagnosticus was once considered the forerunner of all bird-hipped dinos, and thought not to belong to any great ornithischian group; recent research suggest it could be a very basal Thyreophoran, thus ancestor of Scelidosaurs, Stegosaurs, and Ankylosaurs. From Early Jurassic Southern Africa like Heterodontosaurus, its name derives from the Kingdom of Lesotho, a small South African enclave (once called Basutoland) where its remains were dug out in 1978; the species name diagnosticus underlines its importance to understand early ornithischians evolution.

Merely 3 ft long, even smaller than the already-small Heterodontosaurus, and with a more gracile frame with smaller head and forelimbs, Lesothosaurus was about the bulk of a Compsognathus weighing only 3-4 kg. Unlike the scelidosaurians and the heterodontosaurians, it seems not to have any specialization in its anatomy. Its mouth had simple teeth not apt for proper grinding but only to tear vegetation off to the plants (just like the contemporaneous prosauropods); it probably had only small cheeks, but had already the lower toothless bill (technically, the "predental bone") which is actually the main hallmark of every ornithischian (other than the shape of the pelvic bones of course).

Its forelimbs were short and five-digited, its hindlimbs apt for running, its tail long and flexible (its vertebrae lacked the bony tendons of more evolved birdhipped dinos) and it not shows signs of armor on its body. Finally, its pelvis lacked the "prepubis", a forward-pointing prominence of the pubis typical of all the main/most evolved ornithischian lineages (the scelidosaurs and heterodontosaurs also lacked it). Because of the body-shape popular dino-books often give to it, it was said that Lesothosaurus "resembles a lizard more than any other dinosaur", but in other illustrations Lesothosaurus looks more like an undersized Hypsilophodon than to a long-legged lizard. Interestingly, it's also hypothized that Lesothosaurus underwent long "hibernations" to survive the harsh desertical conditions of the habitat it lived within, but this is not yet demonstrated.

About this dinosaur there are the same issues of Heterodontosaurus in pop-portrayals: it can be shown living alongside Plateosaurus and the triassic species of Coelophysis, despite being from Early Jurassic and not Triassic like the other two, and can be shown as a coelophysis' prey — given its size and lack of defenses outside running, this could be possible if the two met in Real Life. Like the heterodontosaur, Lesothosaurus can also be cited as an example of a particularly small herbivorous dinosaur.

  1. Entry Time: undetermined
  2. Trope Maker: Popular dinosaur books

Other primitive dinosaurs

Sorry, these aren't here. If you're looking for Fabrosaurus, Eocursor, Scutellosaurus, Tianyulong, and others, see here.


How well does it match the trope?

Example of:


Media sources: