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1[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/250px_ornithischia.png]][[caption-width-right:250:Ornithischian Pelvis]]
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3This page is about the stock [[http://en.wikipedia.org/wiki/Ornithischia ornithischian]] dinosaurs. Ornithischians ("bird-hipped dinosaurs") included a variety of usually herbivorous dinosaurs, like Ceratopsians, Stegosaurs, Ornithopods, and Ankylosaurs: some big and other small, some bipedal and other quadrupedal, and others in part bipedal in part quadrupedal. All were united by their skeletal anatomy, especially their specialized jaws and pelvis (the pelvis is in the image above). Unlike the saurischians, they were definitely a natural grouping of dinosaurs, having risen in the Triassic from a still-unknown common ancestor. They eventually went extinct 66 mya in the Mass Extinction that ended the Mesozoic, this time without leaving descendants.
4
5----
6
7[[foldercontrol]]
8
9----
10
11!Armor-bodied Plant-Eaters
12
13The [[http://en.wikipedia.org/wiki/Thyreophora Thyreophorans]] ("shield bearers"), were a group of dinosaurs notable for their body armor made of bony plates covered with horny sheaths. Many also developed [[BewareMyStingerTail weapons on the tips of their tails]]. All but the most primitive forms were massive quadrupedal animals belonging to one of these two groups: [[http://en.wikipedia.org/wiki/Stegosauria stegosaurians]] and [[http://en.wikipedia.org/wiki/Ankylosauria ankylosaurians]].
14
15[[folder:Stegosaurians]]
16
17Stegosaurians 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 and the largest known member, while ''Kentrosaurus'' was one of the smallest and spikiest of them. ''Tuojiangosaurus'' was rather in the middle of the two both in size and in look.
18
19!! Plates as Solar Panels?: ''[[http://en.wikipedia.org/wiki/Stegosaurus Stegosaurus]]'' ***
20[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/stegosaurus_-_copia_4758.jpeg]]
21[[caption-width-right:350:[[http://pilsator.deviantart.com Armored Roof Lizard]]]]
22
23One 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 [[http://en.wikipedia.org/wiki/Stegosaurus_in_popular_culture in films and in cartoons]]. It lived in Late Jurassic North America, 155 to 150 million years ago, and was discovered during the Bone Wars like several other dinosaur species (''Allosaurus'', ''Diplodocus'', ''Brontosaurus'' etc.) [[note]]but not ''Tyrannosaurus'': this one was found well after the end of the Wars.[[/note]]
24
25The several ''Stegosaurus'' species ranged from 24ft/7.5m up to 30ft/9m 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 look bigger than it was when seen from the side: actually, the stegosaur’s body was laterally flattened, and not as heavy as it seems. Its limbs were pillar-like; the front legs were much shorter than the hind legs, 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", but actually it was larger than a walnut, closer to an apple in size. This has made it the most iconic dinosaur within the DumbDinos trope, though sauropods, also with small brains, 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, hindlegs and tail, and/or was partially occupied by fat or connective tissue. Not mentioning that this extra space in the sacrum is present also in modern reptiles/birds (except for the legless ones, like snakes) for these purposes.
26
27The plates are the distinctive stegosaurian feature, and every stegosaur portrait shows them: without them, stegosaurs would be easily mistaken for kinda sauropod things. 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 [[http://scienceblogs.com/tetrapodzoology/2011/01/10/stegosaur-skin-plates-sex/ study on stegosaur skin impressions]] suggests the former is more likely. Defense, thermoregulation, and display (mating or threat) are the classic hypotheses, but we have no definitive proof for any of these ideas. 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 too irregularly placed to be used as armor, leaving the animal's sides unprotected -- although if covered in horn, they might have had sharp edges, which would make them more effective as defense. The "solar panel/radiator" theory has been one of the most popular since the Dino-Renaissance: it could explain why they were apparently so rich in blood vessels (their tissue was very spongy), and also the singular arrangement of these plates -- they were asymmetrically-placed, giving more surface to solar rays. This theory is a concrete possibility, as studies on crocodilian scutes (also rich in pores and cavities) and turtle shells show they have usage for thermoregulatory purposes. ''Series/WalkingWithDinosaurs'' 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 if seen from the side, or communicating with others of its kind by changing hypothetically their colors, like what some modern reptiles do with their appendages. It's probable that all three theories are partially or completely true.
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29The configuration of these plates [[https://youtu.be/rgqQNBuGGWg was until recently debated]]. Although ''Stegosaurus'' has left dozens of specimens, they are usually found with misplaced plates, making them sort of a 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. Interestingly, all of ''Stegosaurus''' relatives displayed paired lines of plates, making the "stego" unusual for its kind.
30
31''Stegosaurus''' tail was shorter than that of most sauropods: it was muscular and flexible but not ending with a narrow "whip" like in diplodocid sauropods. 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 hypothesized about sauropods. When swung from side to side, this tail made a [[BewareMyStingerTail powerful weapon]] [[ToughArmoredDinosaur against enemies]]. Near the tip of the tail was a group of four long spikes known as ''[[http://en.wikipedia.org/wiki/Thagomizer thagomizers]]'', a term that originates from a ''[[ComicStrip/TheFarSide 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 AscendedFanon than the word "raptors".
32
33Another 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'' would have had shoulder spikes like its relatives. Interestingly, one of the very first portraits of the stegosaur showed it [[https://youtu.be/pQJIVxzIUic with spikes all over its body and a bipedal posture]].
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35It has recently been suggested that ''Stegosaurus'' was [[http://www.livescience.com/50569-stegosaurus-plates-sexual-dimorphism.html sexually dimorphic]] but others have [[http://news.sciencemag.org/paleontology/2015/04/dino-sexing-study-slammed-critics cast doubts on this.]]
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37If 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 [[https://youtu.be/bENtOFR66YY 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 -- the eight spikes portrayal first originated from an early reconstruction of ''S. ungulatus'' made soon after its first scientific description, in late 1800. Or it can have no tail spikes at all. These spikes may be shown as much shorter than in reality: the fossil spikes were about three feet in length, and they might have been covered in horn which would have made them larger. They usually point upwards in images, while in reality they were more sideward-pointing. In some cases the neck is unrealistically long, like Dinny in ''ComicStrip/AlleyOop'', 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. It can be shown with a beak full of teeth, or no beak at all, or fleshy lips and wide mouth opening, like a lizard.
38
39In many old films, ''Stegosaurus'' is shown as a sorta "predestined loser" against big meat-eaters like ''Allosaurus'', ''Ceratosaurus'' or ''[[AnachronismStew Tyrannosaurus]]'', being too slow to defend itself effectively. In modern portrayals, however, ''Stegosaurus'' [[TookALevelInBadass more often wins fights]] [[ToughArmoredDinosaur with the aforementioned carnivores]], like in ''Series/WalkingWithDinosaurs'', as it is now considered to be agile and flexible in spite of its slow running speed and heavy body. Living in herds, as shown by the abundance of specimens in fossil record (it's believed the most common dino in the [[http://en.wikipedia.org/wiki/Dinosaur_National_Monument Dinosaur National Monument]]), gave it further protection. No eggs and nests are known, but there are many specimens of young individuals, with smaller plates/spikes and bigger heads than the adults.
40
41# '''Entry Time:''' 1912
42# '''TropeMaker:''' ''Literature/{{The Lost World|1912}}''
43
44!! How many Spikes you Have: ''[[http://en.wikipedia.org/wiki/Kentrosaurus Kentrosaurus]]'' *
45
46If 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'', full-name ''Kentrosaurus aethiopicus''.
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48Only half the length of ''Stegosaurus'', 4 meters, and weighing much less than it, it was one of the smallest members 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 zigzagging), 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". Studies of its hips also tell us it had an insanely good turning radius, suggesting it would have protected itself from predators by constantly turning its shoulder and back spikes towards them and its head away from their claws and teeth.
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50A Late Jurassic animal like ''Stegosaurus'', ''Kentrosaurus'' was discovered in the 1910s in the same East African site along with much bigger dinosaurs like ''Giraffatitan'', ''Dicraeosaurus'', and ''Tornieria'' (which could easily trample it if it was not careful); the two stegosaurians couldn't have met each other in reality. Dozens of ''Kentrosaurus'' skeletons have been discovered but, like ''Stegosaurus'', with plates/spikes scattered away. Thus, scientists once thought ''Kentrosaurus'' side spikes [[ScienceMarchesOn 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.
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52One mention about [mis-]spelling: '''K'''entrosaurus should ''never'' be confused with '''C'''entrosaurus. Both names mean "pointed lizard", but the "points" of ''Centrosaurus'' were on its head: it was a ''ceratopsian''. Some scientists have raised concerns about this, leading to efforts to rename ''Kentrosaurus'' by such names as "Kentrurosaurus" ("pointed-tailed lizard") and "Doryphorosaurus" ("lance-bearing lizard), but the rules of scientific naming mean none have stuck.
53
54# '''Entry Time:''' 1988
55# '''TropeMaker:''' ''WesternAnimation/DinoRiders''
56
57!! The Unpronounceable: ''[[http://en.wikipedia.org/wiki/Tuojiangosaurus Tuojiangosaurus]]'' *
58
59Together with ''Kentrosaurus'', the most portrayed non-''Stegosaurus'' stegosaur in popular dino-books has been ''Tuojiangosaurus'' ("Tuo River lizard") -- don't worry if you cannot pronounce that "jiang" correctly, unless you are Chinese or Chinese-speaking of course. Its whole scientific name is ''Tuojiangosaurus multispinus'', "many-spiked Tuo River lizard". Other two classic Late Jurassic dinosaurs from the same country have also geographically-referenced names, ''Mamenchisaurus'' (after Maming Brook) and the allosaur-relative ''Yangchuanosaurus'', after the Yongchuan district in the city of Chongqing.
60
61Discovered in 1977 and described by Chinese paleontologist Dong Zhiming, ''Tuojiangosaurus'' was overall more similar to ''Stegosaurus'' than to ''Kentrosaurus'' (some quote it as the stegosaur's "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 intermediate between ''Kentrosaurus'' and ''Stegosaurus''. ''Tuojiangosaurus'' had narrow, paired plates like the former, but a four ([[ComicStrip/TheFarSide thagomizers]]) 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 uncertain whether it really 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''.
62
63''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. The tuojiangosaur appears also in ''Jurassic World: The Game'' as one of the dinosaurs cloned in the park.
64
65# '''Entry Time:''' 2010s
66# '''TropeMaker:''' ''VideoGame/JurassicWorldTheGame''
67
68!! Other stegosaurians
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70Sorry, these ones aren't here. If you're looking for ''Dacentrurus'', ''Huayangosaurus'', ''Wuerhosaurus'', ''Chialingosaurus'', ''Chungkingosaurus'', ''Lexovisaurus'', ''Loricatosaurus'', ''Gigantspinosaurus'', ''Miragaia'', and others, see [[UsefulNotes/PrehistoricLifeStegosaurs here]].
71[[/folder]]
72
73[[folder:Ankylosaurians]]
74
75These are the most well-armored among all the dinosaurs (sometimes called ''the'' armored dinosaurs), with low wide frames, a 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.
76
77Ankylosaurians were once divided in only two families: ankylosaurids (clubbed) and nodosaurids (club-less). Ankylosaurids (among them ''Ankylosaurus'', ''Euoplocephalus'', ''Scolosaurus'', and ''Pinacosaurus'') had a broad head, armor plates that formed a keratin-covered shell with short spikes in many directions, and a [[BewareMyStingerTail tail]] [[EpicFlail club]] in all but the most primitive forms; proper nodosaurids (including ''Nodosaurus'', ''Sauropelta'', and ''Edmontonia'') 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 the nodosaurids: the polacanthines (including ''Polacanthus'' and until recently, ''Gastonia'', and possibly ''Hylaeosaurus''), variably classified as either closer to ankylosaurids or to nodosaurids. The short-named ''Minmi'' of Australia and the "south-polar" ''Antarctopelta'' have been hard to classify, but seem to form a unique lineage southern continents-only ankylosaurians called the Parankylosaurians. Finally, the early Jurassic ''Scelidosaurus'' is usually considered basal between stegosaurs and ankylosaurs, but since the 2000s, has often been considered an extremely primitive ankylosaur well outside the three subgroups above.
78
79!! The Living Tank: ''[[http://en.wikipedia.org/wiki/Ankylosaurus Ankylosaurus]]'' **
80
81Popularly as a "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, but usually estimated to be about 20-26 ft (6-8 m). It has traditionally been believed 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 ''Stegosaurus''es. Despite its size, its remains are quite scant, with still no complete skeletons found, and several relatives being more common as fossils. ''Ankylosaurus''[='=] iconic status among ankylosaurians could be explained by [[RuleOfCool its sheer size]] and because its own dinosaurian group is called by its name.
82
83''Ankylosaurus'' has been famous since the 1940s as the most extreme example of an armored dinosaur (although some of its relatives were likely even more heavily armored). 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 TruthInTelevision, even though tyrannosaurs almost certainly didn't prey upon adult ankylosaurs frequently (hadrosaurs were much more abundant and armor-less). Despite their heavy build and short legs, ankylosaurs may have been able to charge the carnivore: their limbs were not pillar-like as the sauropods and stegosaurs, but more similar to those of a rhino or a hippo who are known for their fast charges. Like stegosaurs, ankylosaurs tend today to be portrayed as more agile and active in fights now than in the past: in ''Series/WalkingWithDinosaurs'' one easily [[ToughArmoredDinosaur wins]] the struggle (despite being shown as a very slow-walking animal), delivering to ''T. rex'' a fatal blow with its tail mace. When the tyrannosaur is shown winning the battle, it's seen "overturning" the ankylosaur to expose the soft vulnerable underbelly and devouring its flesh there.
84
85Most herbivorous or omnivorous dinosaurs are often depicted in media as gregarious animals: scenes involving herd-dwelling sauropods/ceratopsians/stegosaurs/[[SocialOrnithopod hadrosaurs/iguanodonts]]/ornithomimids are a very common sight. On the other hand, ankylosaurians are usually depicted as loners. This is realistic, because their fossils are rarer 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. It seems that baby ankylosaurians gathered in groups, as their armor wasn't fully developed yet.
86
87''Ankylosaurus'' probably retains the 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 justifies 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 RealLife fossils, the club usually appears two-lobed like that of a ''Euoplocephalus'' (a close relative commonly depicted in popular dino-books), instead of elliptical.
88
89The 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 ''Ankylosaurus''es: see the aforementioned finale of ''Series/WalkingWithDinosaurs'', in which ''Ankylosaurus'' has keeled plates instead of true spines. Finally, the broad head should have four horns behind the eyes and the ends of the mouth, but hornless ''Ankylosaurus''es are not unseen elsewhere.
90
91Ironically, one of the few plausible ankylosauruses in cinema is the [[AllAnimalsAreDogs dog-like]] Url from Disney's ''WesternAnimation/{{Dinosaur}}'': he was highly undersized, but this may be justified if he was young. Another is in the controversial documentary ''Series/ClashOfTheDinosaurs'', qualified by many as a DocumentaryOfLies, but at least has the merit to show the correct shape of its head. Still another rather correct ''Ankylosaurus'' is in TheNineties-related ''Series/PlanetOfDinosaurs''.
92
93Many other inaccuracies seen in ankylosaur portrayals are substantially the same as the stegosaurs. 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 they were much smaller-sized, stegosaurians and ankylosaurians tend to be shown as slow-moving as the sauropods: ex. the aforementioned Url 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 ''WesternAnimation/TheLandBeforeTime'' appears even slower than the sauropods of the same film (the latter have correct upright limbs, though).
94
95# '''Entry Time:''' 1940s
96# '''TropeMaker:''' "The Age of Reptiles" mural
97
98!! Artistic Armor: ''[[http://en.wikipedia.org/wiki/Euoplocephalus Euoplocephalus]]'' *
99
100''Ankylosaurus magniventris'' ("big-bellied fused lizard") was the first clubtail recognized (1908), but, as said above, its remains were very scanty; however, its assumed 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).
101
102''Euoplocephalus tutus'' 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]]Just like ''Centrosaurus'' and so on which were smaller than their "younger" relative ''Triceratops''.[[/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 in its corners, and ''bony eyelids''. Finally, the [[{{Pun}} club]] was trefoil-shaped and almost resembled the [[{{Pun}} 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 cutleri'', see just below. Rooter, from ''WesternAnimation/TheLandBeforeTime'', is probably the most famous example of this.
103
104A really cool animal to draw, anyway, whatever the name: in fact, ''Euoplocephalus''/''Scolosaurus'' appears as the actual stock ankylosaur in many dinosaur books. It's also worth noting that several alleged ''Ankylosaurus'' seen in books, documentaries, films, and toylines 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'' and ''Scolosaurus'' are typically [[OvershadowedByAwesome not portrayed]] in CGI documentaries, which will prefer their gigantic cousin -- the fact that ''Ankylosaurus'' could fight ''T. rex'' while "Euoplo" and "Scolo" only had ''Gorgosaurus'' and ''Daspletosaurus'' to battle doesn’t help. Some dino-books wrongly portray ''Scolosaurus''/''Euoplocephalus'' living and fighting against ''Tyrannosaurus rex'', which actually [[AnachronismStew lived later]].
105
106# '''Entry Time:''' 1940s
107# '''TropeMaker:''' Zdenek Burian's painting (actually ''Scolosaurus'')
108
109!! Club or Spikes?: ''[[http://en.wikipedia.org/wiki/Scolosaurus Scolosaurus]]'' *
110
111Late Cretaceous North America has several examples of dinosaurs that were very common in older popular dino-books but now have been "substituted" in their role by close relatives. The carnivorous ''Gorgosaurus'' was synonymized with ''Albertosaurus'' between the 1970s and the 2000s, though this has been reversed, and it is now a valid genus again; the hadrosaur ''Kritosaurus'' was revealed to be based upon the related ''Gryposaurus'' in the 1990s (although it is still a valid genus); the ceratopsid ''Monoclonius'' is today thought by several experts as a non-diagnostic juvenile centrosaur; and the small deinonychosaur ''Stenonychosaurus'' was synonymized with ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Troodon]]'' since the 1980s but now it has again resurrected (with ''Troodon'' being rendered dubious). All this to not mentioning the notorious ''Trachodon''/''Edmontosaurus''/''Anatosaurus''/''Anatotitan'' case. The original specimen of ''Euoplocephalus'' was discovered in 1902, but between 1923 and 1929, three other genera very similar to it (''[[UsefulNotes/PrehistoricLifeAnkylosaurs Dyoplosaurus]]'', ''Scolosaurus'', and ''[[http://en.wikipedia.org/wiki/Anodontosaurus Anodontosaurus]]'') were named. All these three were combined into ''Euoplocephalus'' in 1971, but were rescued from the Invalid Box between 2007 and 2013 after showing that some patterns of armor were useful in classifying their owners.[[note]]For example, the ''Dyoplosaurus'' club was different from that of ''Euoplocephalus'', being longer than wide. ''Anodontosaurus'''s club had pointed ends like a giant pickaxe, causing it to vaguely resemble outdated portrayals of ''Scolosaurus''. ''Dyoplosaurus'' was also older than most ''Euoplocephalus'' specimens, while ''Anodontosaurus'' lived after the latter but before ''Ankylosaurus''.[[/note]]
112
113''Scolosaurus'' is known from one really well-preserved skeleton from Alberta and several more incomplete specimens from Montana (the latter of which are sometimes given their own genus, ''Oohkotokia''). It was about the same size as ''Euoplocephalus'', lived in the same age, had a similar head but with longer, more swept-back horns, and a club also similar in shape. The main point is: the famous armor of ''Euoplocephalus'' made of differently-shaped plates has been found to actually pertain to ''Scolosaurus'', while the real ''Euoplocephalus'' had less complex armor. The classic "Euoplocephalus" portrayals of the 1980s and 1990s are actually based on the aforementioned well-preserved ''Scolosaurus'' found in Alberta. This skeleton, nonetheless, lacked the skull as well as the clubbed tip of its tail, making its tail look shorter and ending with a single pair of spikes, which were actually in the middle of the tail.
114
115Several old books and models have portrayed the resulting "stegosaur-tailed ankylosaur", wrongly showing it with much more generic armor than the RealLife fossil. They usually named it correctly as "Scolosaurus", but sometimes "Euoplocephalus" or even "Ankylosaurus": the ur-example is the picture by Zdenek Burian which shows this critter defending itself against a ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Gorgosaurus]]''. Though few noticed, even [[WesternAnimation/TheLandBeforeTime one very popular work]] has made the same mistake: if observed carefully, the wise "Euoplocephalus" Rooter of the original film has armor analogous to Burian's picture, and also shows the pair of spikes on the tip of its tail when he goes away, revealing he's actually based on ''Scolosaurus''.
116
117# '''Entry Time:''' 1940s
118# '''TropeMaker:''' Zdenek Burian's painting
119
120!! Changes in Look: ''[[http://en.wikipedia.org/wiki/Polacanthus Polacanthus]]'' & ''[[http://en.wikipedia.org/wiki/Nodosaurus Nodosaurus]]'' *
121
122Some decades later the discovery of the first ankylosaurian in England, a companion was added: ''Polacanthus foxii''. English too (some dubious remains from the USA were once also attributed to its genus), and conviving with ''Iguanodon'' and ''Hypsilophodon'' in the Early Cretaceous, ''Polacanthus'' was rather small compared to ''Ankylosaurus'' or ''Euoplocephalus'' being 4m/16ft long, and the first remains found in the Isle of Wight were very incomplete. This explains why in older depictions ''Polacanthus'' had very light armor, consisting only of pairs of long dorsal spikes (hence the name, [[ExactlyWhatItSaysOnTheTin "many spines"]]), a bony shield on its hips, and pairs of small triangular plates on the tail. This kind of armor is typical for the polacanthines, the subgroup of ankies which it's the archetype of. But some portrayals took it a further step, and gave it a stegosaur-like thagomizer, or a small ankylosaurid club. The spiked-tailed polacanth made cameo appearances in ''Film/PlanetOfTheDinosaurs'' and the film adaptation of ''Film/TheLandThatTimeForgot''. The animal has also a more prominent role in the puppet series ''Series/{{Dinosaurs}}'' as Robbie Sinclair's friend Spike, homonymous with the ''Stegosaurus'' non-talking puppy of ''WesternAnimation/TheLandBeforeTime'' franchise.
123
124Today, thanks to a much more complete specimen found in the early 1990s again in England, we know ''Polacanthus'' had an armor that was more extensive and ''Ankylosaurus''-like, though even spikier. The lack of the club and the absence of the thagomizer were proven true. The polacanth appears with this new look in ''Series/WalkingWithDinosaurs'' as a follower of ''Iguanodon'' herds, as well as in most updated portraits in dino-books.
125
126A notable change in appearance has also involved the official archetype of the club-lacking ankylosaurians, ''Nodosaurus textilis''. This was the first ankylosaur discovered in the USA from remains that are more than simple teeth, during the Bone Wars, but still after ''Polacanthus''. "[[UsefulNotes/PrehistoricLifeAnkylosaurs Palaeoscincus]]" is known from isolated teeth found in USA before ''Nodosaurus'', and has been since treated as a dubious wastebasket taxon for undetermined ankylosaur remains. The clubbed ''Ankylosaurus'' and ''Euoplocephalus'' were both found later than ''Polacanthus'' and ''Nodosaurus'', in the early 1900s in Alberta, Canada.
127
128''Nodosaurus'' ("tubercled lizard") was bigger than the ''Polacanthus'', but smaller than ''Ankylosaurus'' proper -- about the size of the ''Euoplocephalus''. Curiously, like what happens sometimes to ''Ankylosaurus'', in classic portrayals, ''Nodosaurus'' is shown with simple armor lacking any spikes. Why? Because the specimen found by Othniel Marsh was devoid of them; in reality, it likely had long spikes protruding from both sides of the body as all other Nodosaurids did. Obviously, we don't know how long these spikes were, since they've never been found.
129
130A strange-looking ''Nodosaurus'' appears in the second sequel of ''WesternAnimation/TheLandBeforeTime'' as one of the three villainous young dinosaurs, aptly named "[[ALizardNamedLiz Nod]]", together with two equally unrealistic companions, a ''Hypsilophodon'' named "[[ALizardNamedLiz Hyp]]" and a ''Muttaburrasaurus'' called "[[ALizardNamedLiz Mutt]]" (both ornithopods or near-ornithopods). The nodosaur is also frequently shown in classic dinosaur books because of its historical prestige -- usually with the traditional incorrect spikeless shape.
131
132# '''Entry Time:''' 1978 (''Polacanthus''); 1995 (''Nodosaurus'')
133# '''TropeMaker:''' ''Film/PlanetOfTheDinosaurs'' (''Polacanthus''); ''WesternAnimation/TheLandBeforeTimeIIITheTimeOfTheGreatGiving'' (''Nodosaurus'')
134
135!! The Asian Clubtail: ''[[http://en.wikipedia.org/wiki/Pinacosaurus Pinacosaurus]]'' *
136
137Many ankylosaurs are known from Asia. ''Pinacosaurus grangeri'' ("Granger's plank lizard"), the most common in the fossil record, was basically the equivalent of ''Euoplocephalus'' and ''Scolosaurus''. Slightly smaller than them and with a much simpler armor than ''Scolosaurus'', ''Pinacosaurus'' had also a narrower head, a hooked bill, different "horns", and a two-lobed club; it has traditionally regarded as one of the smallest clubbed ankylosaurs, but weighed nonetheless 1 ton or more, like a rhino. Other Asian ankylosaurs, the bigger but younger and less common ''[[UsefulNotes/PrehistoricLifeAnkylosaurs Tarchia]]'' and ''[[UsefulNotes/PrehistoricLifeAnkylosaurs Saichania]]'' were more similar to ''Ankylosaurus''; the older, mid-sized ''Talarurus'' was unusual, being barrel-shaped and short-limbed.
138
139First found in 1920s, ''Pinacosaurus'' was the first armored dinosaur found in Asia, by the same expedition led by Roy C. Andrews that first found ''Velociraptor'', ''Protoceratops'', ''Oviraptor'', and the latter's eggs. Pinacosaur remains found later in the 1950s were wrongly labeled "Syrmosaurus". In 1988, ''Pinacosaurus'' contributed to the ''Dinosaur Renaissance'' by giving 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 led by Dale Russell, Dong Zhiming and Philip Currie, also showed that ankylosaurians were not necessarily loners as traditionally thought. Instead, it seems that young ankylosaurians were gregarious animals, since their armor was much less developed than the adults.
140
141''Pinacosaurus'' has appeared in speculative documentaries or mockumentaries and books about dinosaurs, even though usually unnamed -- or at least, generically called "ankylosaur". Examples include ''Series/PlanetOfDinosaurs'', "The Research of the Dragon", and ''Series/TheTruthAboutKillerDinosaurs''. The first two mention it because of the finding of the juveniles dead together: the third, more prosaically, to [[RedShirt give a prey]] to ''Velociraptor'', just like what happens to ''Protoceratops''. Being the adult ''Pinacosaurus'' 15 ft long, far bigger than the 6 ft long ''Protoceratops'', the programmers chose a juvenile pinacosaur for the "raptor"'s meal. In the show, the dromaeosaur kills ''Pinacosaurus'' by cutting its throat with its sickle-claw after a hard battle.
142
143# '''Entry Time:''' undetermined
144# '''TropeMaker:''' documentary media
145
146!! The First Known Ankylosaur: ''[[http://en.wikipedia.org/wiki/Hylaeosaurus Hylaeosaurus]]'' *
147
148Huge ''Ankylosaurus'' has not always been THE ankylosaur. It was discovered at the beginning of the 20th century, but several relatives were already known. They were simply smaller, less armored, and above all, very fragmentary, and in the 19th century, were classified among the Stegosaurs. As a group, the Ankylosauria were recognized as distinct only after ''Ankylosaurus'' was found. With all that in mind, it's interesting that one of the three inspirers of the name “dinosaur” was just an ankylosaur: ''Hylaeosaurus armatus'' ("armored lizard of the forest").
149
150Discovered 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''. Among the famous Crystal Palace Park statues in London made in 1852 by Benjamin W. Hawkings, the Hylaeosaur shows up with the Megalosaur and Iguanodont, and is depicted as larger than it was in RealLife. Unlike the other two "original stock dinosaurs", it has remained totally quadrupedal after [[UsefulNotes/PrehistoricLifeDinosaurs 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 with a lizard-head and long tail, like a simpler version of the Crystal Palace ''Iguanodon'' and ''Megalosaurus''.
151
152''Hylaeosaurus'' usually gets mentioned together with its two companions when the Art/CrystalPalaceDinosaurs sculptures are portrayed in media. In the John Sibbick-illustrated ''Great Dinosaur Encyclopedia'' published in year 1985, ''Hylaeosaurus'' is shown more correctly with a complex armor with sideward-pointing spikes: once considered a nodosaurid because of its lack of club, it is today thought by some to be closely related to ''Polacanthus''. 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.
153
154# '''Entry Time:''' 1854
155# '''TropeMaker:''' [[Art/CrystalPalaceDinosaurs Crystal Palace Park]]
156
157!! The Unfair Sex: ''[[http://en.wikipedia.org/wiki/Sauropelta Sauropelta]]'', ''[[http://en.wikipedia.org/wiki/Edmontonia Edmontonia]]'', & ''[[http://en.wikipedia.org/wiki/Gastonia_(dinosaur) Gastonia]]'' *
158
159Several dinosaurs have received a Latin name ending with the unusual feminine suffixes ''-a'' or ''-ia'': this is true especially for ankylosaurians, but also for many other dinosaur subgroups -- sauropods like ''Jobaria'', theropods like ''Nedcolbertia'', stegosaurians like ''Miragaia'', basal ornithischians like ''Leaellynasaura'', and, more famously, the egg-caring hadrosaur ''Maiasaura''. Among the ankylosaurians ending in ''-a'' the most well-known have probably been ''Sauropelta'', ''Edmontonia'', and ''Gastonia'', all Cretaceous, North American, and clubless.
160
161''Gastonia burgei'' was a middle-sized 4.5 m long ankylosaur from the Early Cretaceous, smaller than the 7 m long Late Cretaceous ''Edmontonia longiceps'' and the even larger (7.5 m) but slightly later in the Early Cretaceous ''Sauropelta edwardsorum''. Generally, clubless ankylosaurians were smaller compared with the clubbed ankylosaurids. Discovered in 1998 in Utah, several decades after the other two, the ''Gastonia'' was related to the European ''Polacanthus'', and shared with it the same spiky body and tail and the hip scutes. The ''Edmontonia'' and ''Sauropelta'' were more closely related to ''Nodosaurus'', with long shoulder spines, no scutes above the hip, and tails lacking the long spikes of ''Gastonia'' and ''Polacanthus''.
162
163 ''Edmontonia'' had a pair of often double-pointed shoulder spikes pointing forwards like horns, and was able to deliver fatal wounds with them when it charged like a rhino or a hippo against tyrannosaurids like ''Albertosaurus''. ''Sauropelta'' too had a pair of huge spikes on its shoulders, pointing more upwards and not double-pointed but equally threatening, this time used against big allosauroids like ''Acrocanthosaurus'' (tyrannosaurids still didn't exist at ''Sauropelta'''s times).
164
165''Gastonia'' has recently become popular in paleo-media, both because its armor was especially spiky and impenetrable among ankylosaurians, and because lived just alongside the famous "giant raptor" ''Utahraptor'' -- both dinosaurs were found in the same geological formation. ''Gastonia'' and ''Utahraptor'' have become [[AnimalJingoism stock enemies]] as they become better known, but its likely that in reality, ''Utahraptor'' would have preferred hunting the much less heavily defended mid-sized iguanodontians and basal therizinosaurs it also lived alongside.
166
167# '''Entry Time:''' 2008 (''Gastonia''), 2009 (''Sauropelta''), 2011 (''Edmontonia'')
168# '''TropeMaker:''' speculative documentaries
169
170!! Ankylosaurs of the Southern World: ''[[http://en.wikipedia.org/wiki/Minmi_(dinosaur) Minmi]]'' & ''[[http://en.wikipedia.org/wiki/Antarctopelta Antarctopelta]]'' *
171
172Non-stock ankylosaurs and stegosaurs tend often to be ignored in visual media. Maybe their reputation of “slow and foolish” has done its part, even though [[ToughArmoredDinosaur this fame is undeserved]]. A good example of missed opportunity was a small ankylosaur discovered in Australia in 1980, with one of the least dinosaurian names one could imagine: ''Minmi'', aka "the shortest-named dinosaur" until the 2000s, when it was beaten by the small theropod ''[[UsefulNotes/PrehistoricLifeBirdlikeTheropods Mei]]'' and then the bat-winged theropod ''[[UsefulNotes/PrehistoricLifeBirdlikeTheropods Yi]]'' in 2015. There is a backstory however: ''Minmi'' comes from “Minmi Crossing”, the locality where its only skeleton was discovered. After a second presumed skeleton was found in the early nineties (reclassified as ''[[http://en.wikipedia.org/wiki/Kunbarrasaurus Kunbarrasaurus]]'' in TheNewTens), ''Minmi'' and this longer-named relative have since then become together the most complete Australian dinosaurs. And yet ankylosaurs do not appear in the ''Series/WalkingWithDinosaurs'' episode "Spirits of the Ice Forest" set in Early Cretaceous, in which ''Muttaburrasaurus'', ''Leaellynasaura'', and the (now considered dubious) “polar allosaur” appear, despite being all contemporaries.
173
174Once considered a nodosaurid, today ''Minmi paravertebra'' is a bit of a taxonomic mystery. At only 10 ft long, it is one of the smallest known, even smaller than the basal ''Scelidosaurus'' but bigger than the dwarf island-dweller ''[[UsefulNotes/PrehistoricLifeAnkylosaurs Struthiosaurus]]'' of Late Cretaceous Europe. ''Minmi'' was devoid not only of tail-club but even of prominent spikes on its body, making it a bit like the primitive ''Scelidosaurus'' indeed. However, its torso was fully covered with small osteoderms of various shapes, its tail had plates, and could even have had some small bony scutes ''in its belly'', a rare thing among ankylosaurs. Its main peculiarity, however, was some unusual internal bones along its backbone called paravertebras (lit. "beside vertebra"), which according to some allowed the ''Minmi'' to run faster than other ankylosaurs -- hence its full name ''M. [[MeaningfulName paravertebra]]''.
175
176The Australian ''Minmi'' was the first ankylosaur ever found in the southern hemisphere, in 1980, but it was steadily joined by a second animal in 1986: another primitive ankylosaur, this time discovered in Antarctica, and maybe related to ''Minmi''. It was the very first dinosaur ever discovered on the Ice Continent, and yet it had to wait ''twenty years'' to be named, in year 2006, as ''Antarctopelta'' appropriately (the first dinosaur named from Antarctica was the Early Jurassic theropod ''Cryolophosaurus'', during the 90s). Since it's known from scant remains, there's not much we can say about it. It's worth remembering however that during dinosaur times, Antarctica was not in the South Polar region, but attached to Australia in the Southern Hemisphere and totally devoid of the immense ice cap. Thus, the ''Antarctopelta'' lived in a non-glacial world like the other Mesozoic dinosaurs, although it would have experienced snow during the winter.
177
178Like ''Minmi'' and ''Kunbarrasaurus'', ''Antarctopelta'' proved difficult to classify for quite a while. Then in 2021, with the discovery of the South American ''[[UsefulNotes/PrehistoricLifeAnkylosaurs Stegouros]]'', it was determined that ''Antarctopelta'', together with ''Stegouros'' and ''Kunbarrasaurus'' (and possibly ''Minmi'', which ''Kunbarrasaurus'' was originally identified as a species of, keep in mind) formed a previously unknown branch of southern hemisphere-only ankylosaurians called the parankylosaurians, which maintained a mixture of primitive and evolved traits not seen in their northern cousins (an example of "mosaic evolution"). ''Antarctopelta'' appears in ''Series/PrehistoricPlanet'', looking for a cave in which to hibernate through the cold polar winter.
179
180# '''Entry Time:''' 1980s
181# '''TropeMaker:''' Their status as the first-known "southern ankylosaurs". ''Antarctopelta'' first appeared in ''Series/PrehistoricPlanet''.
182
183!! The Earliest Tank: ''[[http://en.wikipedia.org/wiki/Scelidosaurus Scelidosaurus]]'' *
184
185When we think about armor-bodied dinosaurs, our minds automatically come to ''Stegosaurus''. But let’s not forget ''Scelidosaurus harrisonii'', a very primitive thyreophoran from Early Jurassic, found in Europe and possibly Asia and North America. If the last is true, it could have met the famous double-crested carnivore ''Dilophosaurus'' in life.
186
1874 m long, half the length of an average ''Stegosaurus'' and small for ankylosaurian standards, the scelidosaur is traditionally considered in the middle between stegosaurs and ankylosaurs, but some have suggested that it's the first true ankylosaur. Still, ''Scelidosaurus'' was slenderer, less heavy, and far less armored than traditionally indended ankylosaurs. Its armor was made only of small bony tubercles sparse in regular lines along its body, limbs, 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''. Its limbs were robust but agile (''Scelidosaurus'' means "limb lizard"), more similar in shape to bipedal ornithischians than to stegosaurs or ankylosaurs sensu stricto, even though some old portraits wrongly show it with stocky limbs similarly to the more advanced thyreophorans. Some scientists have hypothesized it was able to rear up on its hindlegs to reach higher vegetation, like the stegosaurs, but unlike the younger ankylosaurians, which were too heavily armored to do so.
188
189''Scelidosaurus'' is not only a very early animal, it was also a very early find among dinosaurs in general. Its first skeleton has been known since the 19th century ''even before'' ''Stegosaurus'' and ''Ankylosaurus'' were known to science, but it was described later than the Mantell's ''Hylaeosaurus'', by Richard Owen. Like most of the other earliest dino-discoveries, it was found in Europe (in Southern England), and reconstructing its body correctly was a long, hard task. Having a not-so-impressive appearance, ''Scelidosaurus'' has remained a rare-stock animal. However, basal dinosaurs from the Triassic and Early Jurassic often make paleontologists happier than their Late Jurassic or Cretaceous counterparts, because the most ancient dinosaurs help to understand a lot the affinities among the main dinosaurian groups, enhancing the reconstruction of their evolution.
190
191# '''Entry Time''': undetermined
192# '''TropeMaker''': Its status as "the earliest armored dinosaur"
193
194!! Other ankylosaurians
195
196Sorry, these aren't here. If you're looking for ''Borealopelta'', ''Panoplosaurus'', ''Dracopelta'' ''Acanthopholis'', ''Saichania'', ''Sarcolestes'', ''Struthiosaurus'', ''Gargoyleosaurus'', ''Talarurus'', ''Tarchia'', ''Tianchisaurus'', and others, see [[UsefulNotes/PrehistoricLifeAnkylosaurs here]].
197[[/folder]]
198
199----
200
201!Armor-headed Plant-Eaters
202
203The most recent group of ornithischian dinosaurs, the [[http://en.wikipedia.org/wiki/Marginocephalia marginocephalians]] have been usually discovered in Late Cretaceous rocks. They were closer to the ornithopods (see further) than to the thyreophorans (see previous), and are divided in two very different subgroups: the [[http://en.wikipedia.org/wiki/Ceratopsia ceratopsians]] and the [[http://en.wikipedia.org/wiki/Pachycephalosauria pachycephalosaurs]], both unified by their armored heads. The former can be further divided into the more evolved ceratopsids and their more primitive predecessors.
204
205[[folder:Ceratopsians]]
206
207The ceratopsians were a group of dinosaurs characterized by a bony "frill" at the back of their 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 RealLife.
208
209The [[http://en.wikipedia.org/wiki/Ceratopsidae 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: the chasmosaurines (those with long frontal horns, a short nasal horn, and (usually) long frills); and the centrosaurines (those with a short frill, no frontal horns, and (usually) a long nasal horn). ''Triceratops'', ''Torosaurus'', ''Chasmosaurus'', ''Pentaceratops'', and ''Anchiceratops'' are member of the first subgroup, while ''Styracosaurus'', ''Centrosaurus''/"Monoclonius", and ''Pachyrhinosaurus'' belong to the second one. ''Leptoceratops'' and ''Microceratus''/''Graciliceratops'' belong to neither, but were both similar and related to the two guys below.
210
211''[[{{Pun}} Protoceratops]]'' and ''Psittacosaurus'' have been the [[{{Pun}} prototypical]] ancestral ceratopsians. They were much smaller than the proper ceratopsids, roughly as big as a sheep or a pig -- in vivid contrast with their rhino-sized or elephant-sized cousins.
212
213!! T. Rex's Rival: ''[[http://en.wikipedia.org/wiki/Triceratops Triceratops]]'' ***
214[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/triceratops_-_copia_1219.jpeg]]
215[[caption-width-right:350:[[http://pilsator.deviantart.com Horrible Three-Horned Face]]]]
216
217Living 68 to 66 million years ago in Late Cretaceous North America, ''Triceratops'' 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, despite bison living in the Cenozoic (the dating of rocks was still inaccurate at the time). Its name means "three-horned face" after its most prominent feature. It was about 26-30ft/7-9m long and weighed about 5-9 metric tons, and was one of the biggest ornithischian dinosaurs (only some hadrosaurs were larger). Hundreds of skulls are known, but amazingly not a complete skeleton. The biggest known ''Triceratops'' specimen is known with the nickname [[http://en.wikipedia.org/wiki/Big_John_(dinosaur) Big John]].
218
219Two 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; the novel ''Jurassic Park'' mentions "Triceratops serratus" (synonymized with ''T. horridus''. ''T. horridus'' is likely the ancestor of ''T. prorsus'', as the former lived slightly earlier than the latter; this is supported by the existence of several trike specimens that appear to be transitional forms with traits from both species. Another ''Triceratops'' species ''T. hatcheri'', known only from one skull, has been suggested by some to represent a different dinosaur called ''Nedoceratops'' (formerly ''Diceratops'' until it turned out a wasp already had that name), but other scientists think it represents a diseased specimen of ''T. horridus''.
220
221''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 has matched the image of a big herbivorous mammal more than the other stock dinosaurs, to the point we have a [[TemperCeratops trope]] about this. But maybe it's only due to people imagining it as "the only plant-eater [[TheHero able to defeat]] the BigBad ''UsefulNotes/TyrannosaurusRex''" -- even though ankylosaurs and maybe the biggest hadrosaurs might also have been able to defeat ''T. rex'' in a fight.
222
223Its portrayal in the movie ''Franchise/JurassicPark'' of 1993 consolidated ''Triceratops''' popularity even more: the touching scene of the sick ''Triceratops'' with the caring humans around has remained in public consciousness (the 1990 novel has ''Stegosaurus'' in this role), not to mention the strong temper of young character [[ALizardNamedLiz Cera]] of ''WesternAnimation/TheLandBeforeTime'' series that began in 1988. In older films, the trike tend often to be portrayed more like a PrehistoricMonster, like in Creator/RayHarryhausen's ''Film/OneMillionYearsBC''.
224
225Compared to other stock dinosaurs, ''Triceratops'' and its relatives [[https://youtu.be/rgqQNBuGGWg have been portrayed fairly accurately]], and our understanding of their appearance has changed very little over the years. Thanks to their obvious resemblance to rhinos, media ''Triceratops''es have usually been portrayed as agile and active like a modern ungulate mammal; the main mistake in older depictions, other than the aforementioned issue regarding the legs, is [[https://youtu.be/pQJIVxzIUic the wide lizard-like mouth without the typical ornithischian cheeks]]. For a brief period, it was thought that ''Triceratops'' was covered in quill-like bristles like their earlier relative ''Psittacosaurus'', 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. Because of this belief, some have described horned dinosaurs as prehistoric boars, rather than the more classic comparisons with rhinos and buffalos, with some even going as to far as to suggest they were omnivorous[[note]]Like all herbivores do today, they probably would have supplemented their vegetarian diet with a bit of protein every now and then, but they weren't specially adapted to eat other animals[[/note]].
226
227''Triceratops'' and ''T. rex'' have been shown fighting in modern works from the first dino movies and through the whole paleo-artistic tradition (including one especially iconic [[http://www.charlesrknight.com/Enlarge.htm?109 painting]] by Charles R. Knight). In these battles, the percentages of victories between the rex and trike appears to about 50%. Though all this may be TruthInTelevision, it's likely that ''T. rex'' preferred younger and more vulnerable prey than an adult ''Triceratops''. Since it's often considered the badass of the plant-eating dinos, writers can’t resist the urge to make ''Triceratops''es [[TemperCeratops act like rhinos or bulls]]. They’ll be ill-tempered, will charge at everything, and may even ''moo'' like bovines. Another classic trope in paleo-art is showing ceratopsids defending their young by making a barrier around them with their horns and frills pointed against the tyrannosaurids who aim to prey on their offspring, just like musk-oxen actually do against wolves when attacked, or even like what American pioneers did with their wagons against their enemies: this is a possibility, though not proven, conceived during the Dinosaur Renaissance.
228
229The ceratopsids' horn structure was more like cattle's than rhinos': that is, bony protrusions covered with a horny sheath. Their function is still debated: some think the frequently-seen scenes of ''Triceratops'' goring a big carnivore to death or locking their horns like deer in head-vs-head combat might not reflect reality, and that the frontal horns were too fragile and not pointed enough to be used as weapons, instead simply being display devices. However, injuries on ''Triceratops'' specimens match their horns pretty well, as do the presence of bite marks from ''T. rex'' on trike horns (including one that was bitten ''in half'' and showed signs of healing). Additionally, given that the keratinous sheath would have made the horn less likely to break and helped better shape it, goring would still be plausible. However, the most likely answer was "all of the above"; ''Triceratops'' would have mostly used its horns to fight and show off to each other, but when cornered by a hungry ''T. rex'', they would be deadly weapons in a pinch. Interestingly, individual variation is common in ''Triceratops''; some specimens show curved frontal horns, while others had straight horns. The frill was variable too: some individuals had tubercles on the edges, while others had smooth shields. Generally, most media ''Triceratops''es have [[RuleOfCool tubercled frills]].
230
231The 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, again falling in TemperCeratops. 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 RealLife, the ceratopsians' jaws were the strongest among all plant-eating dinosaurs, filled with sharp cutting teeth behind the parrot bill, but they were arguably adapted to eat fibrous plants, not to tear meat -- or at least this was not the main function. Some think 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 further, or they may have been only for display.
232
233There ''is'' one thing that most paleomedia gets wrong, though - portraying ''Triceratops'' as living in large herds. Unlike many of its relatives, ''Triceratops'' fossils have never been found in bonebeds containing dozens of individuals, indicating they were either solitary or lived in small groups. The latter theory would ultimately be confirmed in 2024, when five individuals were found at one site.
234
235# '''Entry Time:''' 1918
236# '''TropeMaker:''' ''Film/TheGhostOfSlumberMountain'' (film)
237
238!! Crowned Head: ''[[http://en.wikipedia.org/wiki/Styracosaurus Styracosaurus]]'' **
239[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/styracosaurus_-_copia_6991.jpeg]]
240[[caption-width-right:350:[[http://pilsator.deviantart.com Alberta's Spiked Lizard]]]]
241
242Several 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 like ''Centrosaurus'' or ''Pachyrhinosaurus'', this makes it the usual RuleOfCool example.
243
244''Styracosaurus albertensis'' ("Alberta's thorny lizard") 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". Most North American Cretaceous dinosaurs were actually described during this "rush", but only the coolest-looking ones joined the stock dinosaur ensemble. About half as long as ''Triceratops'', only 18ft/5.5m and 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'' (built completed 1886, well before its discovery). ''Styracosaurus'' had also shorter and stronger jaws than ''Triceratops''. Based on huge bonebeds containing hundreds of individuals, some speculate it was more sociable than ''Triceratops''es and lived in larger herds.
245
246''Styracosaurus'' frill spikes were ''not'' true horns as commonly said, but only an exaggerated version of those protuberances commonly seen in 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 (like in Disney's ''WesternAnimation/{{Dinosaur}}'') or more in popular works, or even with no frill and the spikes protruding directly from the back of the neck like the horned lizard of the deserts of North America.
247
248Why 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 an exception, having a solid frill without holes). The frill could have been raised for threat display. Another hypothesis is that it was a thermoregulating device: like ''Stegosaurus''[='=] plates, the ceratopsian 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. It is also possible that frills show sexual dimorphism and were brightly colored in either male or female individuals when alive. Ultimately though, it's completely impossible that like with ''Stegosaurus''' plates, all of these theories were at least partly true.
249
250The styracosaur has appeared in several works since the first portrayal in 1933 (in ''Film/TheSonOfKong''), and is also common in toys and popular books. On the other hand, recent documentaries haven't represented it so frequently. Maybe because in RealLife, ''Styracosaurus'' didn't live at the right time period to battle ''Tyrannosaurus'' as ''Triceratops'' did, but only smaller carnivores like ''Gorgosaurus'' and ''Daspletosaurus''.
251
252# '''Entry Time:''' 1933
253# '''TropeMaker:''' ''Film/TheSonOfKong''
254
255!! The Biggest Skull?: ''[[http://en.wikipedia.org/wiki/Torosaurus Torosaurus]]'' *
256
257''Torosaurus latus'' was mainly made famous by ''Series/WalkingWithDinosaurs'' 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 (such as ''WesternAnimation/DinoRiders'' & various paleoart) because of its huge skull, long believed the biggest of any land animal that ever existed -- 8-9 ft long, taller than an adult person if stood 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 look bigger than it actually was if seen from the front. According to some, the choice to give the main role to ''Torosaurus'' instead of ''Triceratops'' was just because of [[RuleOfCool its bigger frill]].
258
259''Torosaurus latus'' was described during the Bone Wars by Marsh as a distinct ceratopsid genus from ''Triceratops''. It was basically identical to the latter, only with a much longer frill that reached the shoulders when held horizontally: this shield was smooth-edged and with the typical two openings hidden by skin in life. ''Triceratops'' lacked these openings: indeed, "Torosaurus" means "open lizard" precisely because of this, and ''not'' "bull lizard" as stated in many sources. ''Toro'' means "bull" in Spanish and Italian, but the Latin word is spelled ''taurus''. The torosaur lived in the same places and epoch as ''Triceratops'', the extreme Late Cretaceous North America, but its fossils have always been rarer than the latter.
260
261In 2010, some scientists proposed that ''Torosaurus'' may not have been its own genus 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'', created a few years after the name ''Triceratops'', would be retired and ''Triceratops'' would remain in use. In any case, there is still good reason to believe that ''Torosaurus'' is a valid genus. ''Torosaurus'' fossils have been found in areas where ''Triceratops'' fossils have not, and at least one sub-adult ''Torosaurus'' specimen is known.
262
263# '''Entry Time:''' 1988
264# '''TropeMaker:''' ''WesternAnimation/DinoRiders''
265
266!! Five Horns?: ''[[http://en.wikipedia.org/wiki/Pentaceratops Pentaceratops]]'' & ''[[http://en.wikipedia.org/wiki/Titanoceratops Titanoceratops]]'' *
267
268Despite many of the most well-known ceratopsian genera having the usual "-saurus" ending (not only ''Torosaurus'' and ''Styracosaurus'' but also ''Centrosaurus'', ''Pachyrhinosaurus'', ''Chasmosaurus'' and others), most described kinds have the same suffix of the Great-Stock member. ''-ceratops''es abound here: after ''Triceratops'' ("three horned face") and ''Protoceratops'' ("first horned face", because it was a ceratopsid predecessor), the most well-known is ''Pentaceratops'' ("''five horned'' face"). But did it really have 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 large in ''Pentaceratops''. One of the classic chasmosaurine ceratopsids, ''Pentaceratops sternbergii'' looked practically like an intermediate form between ''Torosaurus'' and ''Chasmosaurus'': smaller than ''Torosaurus'' but bigger than ''Chasmosaurus'', lived before the former but around the same time as the latter. Its horns were shorter than ''Torosaurus'' but more developed than ''Chasmosaurus''. Its frill was neither elliptical/smooth like the torosaur's, nor triangular/complex like the chasmosaur's: it was rectangular, and lightly serrated around its whole perimeter like that of many ''Triceratops''es. The frill openings of ''Pentaceratops'' were very wide, like those of chasmosaurs, compared to the smaller ones of ''Torosaurus''.
269
270Known since the first half of the 20th century from remains discovered in New Mexico, ''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 2.5m-long skull, bore the record for the biggest-headed land animal ever; this putative ''Pentaceratops''' skull was ''3 m long''. [[ScienceMarchesOn Science Has Marched On]] however, and this specimen has been deemed a separate animal in January 2011, meaningfully named ''Titanoceratops'' (although there are still those who maintain it's just a large ''Pentaceratops''). ''Pentaceratops'' has appeared in the video game ''VideoGame/JurassicWorldEvolution'' as one of the cloned dinosaurs in the park, but otherwise has little pop cultural presence.
271
272# '''Entry Time:''' 2018
273# '''TropeMaker:''' ''VideoGame/JurassicWorldEvolution''
274
275!! Immense Herds: ''[[http://en.wikipedia.org/wiki/Centrosaurus Centrosaurus]]'' & "[[http://en.wikipedia.org/wiki/Monoclonius Monoclonius]]" *
276
277If you think ''Triceratops'' was the ultimate rhino-dino, it's only because you have never heard about ''Centrosaurus''. Like ''Styracosaurus'', the latter had a look that ''literally'' resembled a rhinoceros. Its nasal horn was much longer compared to ''Triceratops'', and was maybe 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'', reinforcing even more the rhino resemblance. About the frill, it was rather short and undulating-edged, with that pair of bony openings covered with skin in the living animal, present in most ceratopsians outside ''Triceratops'' and a few others. But the most unexpected thing is a pair of bony “hooks” curving downwards from the top of the shield; for some inexplicable reason they are often taken out in ''Centrosaurus'' models or drawings. Its name, "pointed lizard", do refer to these hooks and not to its long nasal horn as one could expect. The full name is ''Centrosaurus apertus'' ("apertus" = open, a reference to the frill-holes).
278
279Named in the beginning of the 20th century, most of its remains were then attributed to another relative, "Monoclonius crassus", 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 ''Centrosaurus''es that had died together, probably killed while trying to cross a river in a flood. This discovery was one of the first pieces of concrete evidence for migrating behaviour in dinosaurs, a bit like modern caribou and wildebeest, which also sometimes die en masse during their river crossings. Since then, ''Centrosaurus'' has mainly replaced "Monoclonius” in books/docus as “the one-horned ceratopsid”.
280
281Another centrosaur graveyard, even bigger by number of specimens, was found around 2010 in Alberta, and is believed today by many the biggest dinosaurian bonebed of the whole world, named the [[http://en.wikipedia.org/wiki/Hilda_mega-bonebed Hilda mega-bonebed]]. Curiously, the centrosaur was unnecessarily renamed "Eucentrosaurus" in year 1988, but returned to ''Centrosaurus'' again soon after. It should not be confused with the small stegosaur ''Kentrosaurus'', which was Jurassic (70 my earlier) and only half the bulk of it. To avoid confusion, one can pronounce them differently: "sEn-trO-[=SAURus=]" the ceratopsian, and "kEn-trO-[=SAURus=]" the stegosaur.
282
283About “Monoclonius” (which doesn't mean "one horn" as sometimes said, but "one sprout"), this one was a very early discovery, made in the 19th century during the Bone Wars, but is now regarded by many as far too dubious to be distinguished from the juveniles of other, better-known centrosaurines. Unlike a lot of other "stock obscure" dinosaurs (the ones signed with one single star here to be clear), "Monoclonius" has a notable appearance in popular culture: ''WesternAnimation/PrehistoricBeast'' by [[Creator/TippettStudio Phil Tippett]], who would go on to be a supervisor and consultant for the ''Jurassic Park'' films.
284
285# '''Entry Time:''' 1978 (''Centrosaurus''); 1984 ("Monoclonius")
286# '''TropeMaker:''' ''Film/PlanetOfTheDinosaurs'' (''Centrosaurus''); ''WesternAnimation/PrehistoricBeast'' ("Monoclonius")
287
288!! Triangle-Shield: ''[[http://en.wikipedia.org/wiki/Chasmosaurus Chasmosaurus]]'' *
289
290Math is not always an exclusively-nerd thing. It can also be amusing, especially when you can apply it to dinosaurs. ''Chasmosaurus'' ("chasma" = opening, ravine, fenditure in Greek) can be recognized by the geometry of its frill: strikingly angular in shape, if seen frontally almost like 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 very elongated, almost like the ''Torosaurus'' and ''Pentaceratops'' ones, and was arguably used for the same purpose. But ''Chasmosaurus'' could also have used the two acute points of its shield to scare or harm predators or rivals, like what ''Styracosaurus'', ''Centrosaurus'' and ''Pachyrhinosaurus'' could have done with their frill-spikes -- a task that the smoother-frilled ''Torosaurus'', ''Triceratops'' and ''Protoceratops'' were unable to do. Such spiny headcrests could be confronted with deer and moose antlers, also used as weapons against predators or competitor males.
291
292Compensating this, the rest of the chasmosaur's head was less spectacular than those of the torosaur and trike: the horns were three like ''Triceratops'', but were rather short in comparison -- some individuals had mere hints of the frontal ones; classic hypotheses say they’re from females and/or distinct species. The snout was rather long and narrow compared with that of ''Styracosaurus'' and ''Centrosaurus''. It wasn't an especially big animal either, only about 4 meters long and just over a ton.
293
294Known since the 1910s, ''Chasmosaurus belli'' is one of the most common ceratopsids in the fossil record, and is often considered the archetype of the chasmosaurines in the same way ''Centrosaurus'' is for the centrosaurines. In Fictionland, the chasmosaur was portrayed in a bunch of old movies, and some modern-cartoon "Triceratops" have a suspiciously ''Chasmosaurus''-like triangular frill. Another noteworthy appearance is the doc ''Series/PlanetDinosaur'', which also shows a huge herd of ''Centrosaurus'' dying in a flood.
295
296# '''Entry Time:''' 1970
297# '''TropeMaker:''' ''Film/WhenDinosaursRuledTheEarth''
298
299!! The Ceratops Family: ''[[http://en.wikipedia.org/wiki/Anchiceratops Anchiceratops]]'' & ''[[http://en.wikipedia.org/wiki/Arrhinoceratops Arrhinoceratops]]'' *
300
301As a whole, Centrosaurs - Styracosaurs - Pachyrhinosaurs - Chasmosaurs might be considered the “predecessors” of ''Triceratops''. The latter was elephant-sized, lived 68-66 million years ago just before the [[RockFallsEveryoneDies mass extinction]] and shared its world with the mythical ''Tyrannosaurus rex''; the former were rhino-sized or only a bit larger, lived approximately 77-70 million years ago, and only had to worry about its “humbler” relatives (''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Albertosaurus, Gorgosaurus, Daspletosaurus]]''). If you see a battle between a tyrannosaurid and a ceratopsid in some CGI documentary, [[RuleOfCool expect to see]] more frequently ''Triceratops'' instead of the less gigantic [[{{Portmanteau}} CentroStyracoPachyrhinoChasmosaurs]] and other less-known species, like ''Anchiceratops''. This one was rather ''Chasmosaurus''-like with a similar angular frill that was instead entirely smooth laterally and entirely tubercled at its top, as well as having longer brow horns and smaller frill holes.
302
303A relative and contemporary, ''Arrhinoceratops'', had a similar ornamentation but a shorter frill. Both were less ancient than ''Chasmo/Styraco/Centrosaurus'' but older than ''Triceratops'' and ''Torosaurus''. ''Anchiceratops'' ("almost ''[[UsefulNotes/PrehistoricLifeCeratopsids Ceratops]]''") is abundant in the fossil record, while ''Arrhinoceratops'' is a rarer find; when discovered [[ScienceMarchesOn was initially thought to lack the nasal horn]], hence its prefix “arrhino-”, which means “no horns on the nose”. ''Anchiceratops'' shouldn't be confused with ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Anchisaurus]]'' ("almost lizard"), an ancestral sauropod-relative famous for being the first-found North-American dinosaur -- and according to some, the real inspirer of the character of [[WesternAnimation/TheFlintstones Dino]], the Flintstones' pet dinosaur.
304
305# '''Entry Time:''' undetermined
306# '''TropeMaker:''' documentary media
307
308!! Thick Nose: ''[[http://en.wikipedia.org/wiki/Pachyrhinosaurus Pachyrhinosaurus]]'' *
309
310Ceratopsids are classically known as “horned dinosaurs”: but this one seems not to have liked our definition. ''Pachyrhinosaurus canadensis'' (“thick-nosed lizard of Canada”) and the other species of the same genus (''P. perotorum'' and ''P. lakustai''), at a first glance, resemble more an oversized ''Protoceratops'' than a ''Triceratops'': no true horns on the skull, a thickened boss upon the nose, often described as similar to a lunar crater, and smaller bosses over the eyes. To compensate, the 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, analogous to the pair of "hooks" of ''Centrosaurus''.
311
312Juvenile 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 this animal is a true ceratopsid, more precisely a centrosaurine. ''Pachyrhinosaurus'' was both the largest and the last of the centrosaurines, going extinct 68 million years ago, at the same time its distant relative ''Triceratops'' first appeared. However, it's unlikely the two could have met, because ''Pachyrhinosaurus'' lived much farther north--far north enough to experience snow in the winter, in fact! The biggest species of pachyrhino (''P. canadensis'') was larger than the other species of its ceratopsid subfamily, but didn't reach the size of a ''Triceratops'' or a ''Torosaurus''.
313
314''Pachyrhinosaurus'' was formerly one of the rarest ceratopsids in fossils: then, in the 1990s, a whole herd was discovered in Alaska in the Arctic Circle. The presence of other ''Pachyrhinosaurus'' remains much further south in Canada led scientists to suggest it as proof of migrating behavior among horned dinosaurs, but later studies determined these represented different species (''P. perotorum'' being the Alaskan one and the other two being Canadian). ''Pachyrhinosaurus'' should never get confounded with ''Pachycephalosaurus'': both had something “thick” in their skull, but in the latter’s case, was the ''head'', not the nose. Some could nickname this ceratopsian "the other pachy".
315
316The TurnOfTheMillennium saw a sudden increase in ''Pachyrhinosaurus'' appearances in pop culture, starting as a background character in Disney's ''WesternAnimation/{{Dinosaur}}'', then as a major character in ''[[WesternAnimation/TheLandBeforeTimeVIIITheBigFreeze The Land Before Time 8]]'', and then as the lead role in the ''Film/WalkingWithDinosaurs'' film. It was, at one time, planned to appear in ''Film/JurassicWorldFallenKingdom'', but was replaced with the much more obscure ''[[UsefulNotes/PrehistoricLifeCeratopsids Sinoceratops]]''. ''Series/PrehistoricPlanet'' prominently features a herd of bristly ''Pachyrhinosaurus'' being menaced by a trio of ''Nanuqsaurus'' in the midst of a huge blizzard, leading to a circle-up scene similiar to what is described above under the ''Triceratops'' heading. It seems its oddness among the "classic" ceratopsids has contributed to this formerly unexpected success. Some part of its prominence can also be contributed to specimens being found in Arctic fossil deposits, leading some to imagine it as the dinosaur equivalent of the woolly mammoth or woolly rhino, complete with a speculative coat of insulating down.
317
318# '''Entry Time:''' 2000
319# '''TropeMaker:''' ''WesternAnimation/{{Dinosaur}}''
320
321!! Small Bipedal Trikes: ''[[http://en.wikipedia.org/wiki/Leptoceratops Leptoceratops]]'' & ''[[http://en.wikipedia.org/wiki/Microceratus Microceratus]]'' / ''[[https://en.wikipedia.org/wiki/Graciliceratops Graciliceratops]]''*
322
323Try to tell everyone if the "sheep of the Cretaceous", ''Protoceratops'', was really sheep-like. If you manage to do it, then try with this: ''Leptoceratops'', the same length of ''Protoceratops'' but ''partially bipedal''.
324
325''Leptoceratops gracilis'' ("gracile slender horned face") has probably been the most common basal ceratopsian in docu-media after ''Protoceratops'' & ''Psittacosaurus''; like the former it too was claimed to have been a sort of "proto-sheep", this time not for being very common in fossil record but because it was literally confronted with a sheep by one scientist in TheEighties. ''Leptoceratops'' was the very first small-sized ceratopsian discovered: 1910s, a decade before ''Protoceratops'' and ''Psittacosaurus'', and has often be considered as an intermediate form between the two.
326
327Compared with ''Protoceratops'', ''Leptoceratops'' was not only hornless, but also lacked the "bump" on the nose seen in the former, was notably slimmer-bodied, had longer legs, and possessed a much smaller frill and huge cheek-spikes. There is a surprising thing at this point: contrary to what one might expect, ''Leptoceratops'' lived ''later'' than ''Protoceratops'', at the very end of the Cretaceous; and roamed North America, not Asia, where ceratopsians started their evolution, thus sharing the lands with ''Triceratops'' and ''Torosaurus''. But for some reason, it preserved the archaic bodyplan of its primitive ancestors. Like ''Protoceratops'' and ''Psittacosaurus'', ''Leptoceratops'' could appear a quite harmless creature in a world populated by gigantic dinosaurs: however, it had extremely powerful and massive beaked jaws able to deliver strong bites, and there's also the possibility it had pointy quills on its tail like ''Psittacosaurus''.
328
329Despite their partial bipedality, ''Psittacosaurus'' and ''Leptoceratops'' were still robust guys compared with the “gazelle dinosaur” ''Hypsilophodon'' or the tusked ''Heterodontosaurus''. But they also had some slimmer relatives that if it wasn't for their head, would surely be mistaken for ornithopods. The most historically relevant was aptly called “Microceratops” ("small horned face"). From Ancient Mongolia like the [[RunningGag prototypical]] ''[[RunningGag Protoceratops]]'' (but some 15-20 million years older), it was discovered in the 1950s by a Polish expedition, and was also originally put in the Protoceratopsid family like ''Leptoceratops''. "Microceratops" was long believed the smallest of all the ceratopsians; now the record is disputed by other relatives. It remains one of the smallest dinosaurs ever, only the size of a rooster. It was arguably a quicker-moving animal than most other ceratopsians, thanks to its size and agile legs. Its head was unmistakably (proto)ceratopsian, with any hint of "horns" or "bumps".
330
331Very poorly known scientifically-speaking, “Microceratops” has an unfortunate taxonomic history. Most specimens of this dinosaur were reassigned in 2000 to their own genus ''Graciliceratops'', putting the remaining fossils to dubious to be distinguished from any other primitive ceratopsian. And of top of that, it turned out the name "Microceratops" was already preoccupied by a modern insect (a parasitic wasp), leading the scant material left behind to be renamed ''Microceratus'' ("the small horned-one"). Still, it has appeared in some popular works made before the ''Graciliceratops''-''Microceratus'' mess, namely the first ''Jurassic Park'' novel (here it's the smallest cloned dinosaur, but inaccurately portrayed as a tree-climber), and Disney's ''WesternAnimation/{{Dinosaur}}'' -- this time as the smallest species of the migrating dinosaur herd. It also appeared under the name ''Microceratus'' in ''Film/JurassicWorldDominion''.
332
333# '''Entry Time:''' undetermined for ''Leptoceratops''; 1990s for ''Microceratus'' / ''Graciliceratops''
334# '''TropeMaker:''' their oddness as "small bipedal trike relatives"
335
336!! The First-found Dinosaur Eggs?: ''[[http://en.wikipedia.org/wiki/Protoceratops Protoceratops]]'' **
337[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/protoceratops_-_copia_1232.jpeg]]
338[[caption-width-right:350:[[http://pilsator.deviantart.com Andrew's First Horned Face]]]]
339
340''Protoceratops'' lived 75—71 million years ago in Late Cretaceous Asia, unlike the giant ceratopsids, which were almost exclusively North American in distribution (the Chinese ''Sinoceratops'' being the sole exception). It was around 6ft/1.8m 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".
341
342The most commonly known species of ''Protoceratops'' is ''P. andrewsi'' (from Roy Chapman Andrews, who discovered its remains); a second species exists in ''P. hellenikorhinus'' (the second word means "Greek nose"). At first glance, ''Protoceratops'' resembled a miniaturized ceratopsid like ''Triceratops'': four-legged, with the same robust body, short tail, and unmistakably ceratopsian head. However, it differed from ceratopsids mainly in having no true horns. Other differences include: a simpler frill lacking protuberances (but with the same pair of holes to make it lighter); bigger/thicker cheek spikes; stronger parrot-jaws that almost look like they were compensating the lack of horns; and legs more adapted to running, looking more like those of an ornithopod than those of a ceratopsid (even though incorrectly pillar-limbed protoceratopses are a common sight in media). The sexes might have been dimorphic: larger skulls with a nasal bump and a couple of upper "canine teeth" probably belonged to males -- arguably with the purpose to attract females like deer's antlers and boar's tusks.
343
344First discovered in Mongolia in 1922, ''Protoceratops'' has always been one of the most abundant Asian dinosaurs in fossil record, with hundreds of specimens discovered -- earning it the nickname "the sheep of the Cretaceous". Given the large numbers of animals found together, they probably lived in herds like the bigger true ceratopsids. Many juveniles of the ''Protoceratops'' have also been found, and its growth pattern is one of the best understood among nonbird dinosaurs.
345
346''Protoceratops'' was the most famous Asian dinosaur until ''Franchise/JurassicPark'' made its contemporary ''Velociraptor'' famous. The discoverer of ''Protoceratops'', Roy Chapman Andrews, was an U.S. scientist who fit the AdventurerArchaeologist trope so well, he could have been the ''real'' inspiration for ''Franchise/IndianaJones''. He attributed to it some elongated eggs which now are known to belong to ''Oviraptor'' under the assumption that since the eggs and ''Protoceratops''es were so common they must be connected. These were the very first non-avian dinosaurian eggs ever identified. The original crushed ''Oviraptor'' specimen was found nearby. A classic image in paleo-art is showing ''Protoceratops'' hatching its eggs and [[MamaBear chasing]] or even [[TemperCeratops trampling]] an egg-robbing ''Oviraptor''. However, several nests complete with eggs were found later in Asia, which were ''actually'' laid by protoceratopses. Dinosaur eggshells were porous like those of modern birds to permit the embryos inside to breathe: ''Protoceratops'' laid them in a circular manner, and evidence suggests they were cared for by the parents.
347
348[[https://en.wikipedia.org/wiki/Fighting_Dinosaurs One especially spectacular find]] from 1971 consists of a ''Protoceratops'' and a ''Velociraptor'' locked in combat: they were probably buried by a sudden sandstorm or a collapsing sand dune while fighting. It still remains the best evidence of a "dinosaur battle" between an herbivore and a carnivore even today. 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, presumably attempting to slash it open. The real cause of the battle is uncertain, however: probably the protoceratops was defending itself and/or its offspring from the carnivore, but it's suspected by some that ''Protoceratops'' was the first attacker. In Africa today, buffaloes have been known to suddenly attack lions minding their own business in an effort to eliminate potential threats to their herd, so its possible the ''Protoceratops'' was doing the same thing to the ''Velociraptor''. Many ''Protoceratops'' fossils also have bite marks matching ''Velociraptor'' on them, suggesting the former was a regular prey item for the latter.
349
350Despite its scientific relevance, ''Protoceratops'' is less portrayed in pop-media than ''Triceratops'' and ''Styracosaurus'', likely because of its relatively modest appearance. Perhaps the most well-known protoceratops is B.J., that yellow guy seen in ''Series/BarneyAndFriends''. In the much more beloved book series ''Literature/{{Dinotopia}}'', the talking dino-character who befriends the human protagonists of the first book is a cute ''Protoceratops'' named Bix. This dinosaur appears also in many books and documentaries, usually either as a prey of ''Velociraptor'' (''Series/DinosaurPlanet'' for instance depicts the raptor and proto who end up becoming the abovementioned "Fighting Dinosaurs" fossil) or as the chosen victim of an egg-robbing ''Oviraptor''. ''Protoceratops'' has also gained some notoriety as the possible inspiration for [[OurGryphonsAreDifferent the legend of the griffin]] after folklorist Adrienne Mayor proposed in her book ''The First Fossil Hunters'' that the ancient Scythians saw ''Protoceratops'' fossils during their gold-mining expeditions in Central Asia and attributed them to a half-lion, half-bird beast (four legs, beak, and the frill may have been mistaken for ears or wings). However, this has been called into question, as griffins have been depicted in the art of non-Asian, pre-Scythian cultures.
351
352# '''Entry Time:''' 1940
353# '''TropeMaker:''' ''WesternAnimation/{{Fantasia}}''
354
355!! The Parrot-Dinosaur: ''[[http://en.wikipedia.org/wiki/Psittacosaurus Psittacosaurus]]'' *
356
357Together with ''Protoceratops'', ''Psittacosaurus'' is by far the most important and well-known ceratopsid predecessor. At least, if you ask paleontologists and paleo-fans. RuleOfCool always wins in pop-culture, with small-sized dinosaurs usually rarely getting any consideration by writers or filmmakers -- especially if they are plant-eaters. One rare exception of a fictional psittacosaur is in Disney's ''WesternAnimation/{{Fantasia}}''.
358
359Digression 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 125-100 mya, in the Early Cretaceous; even older and more basal ceratopsians have since been discovered in Late Jurassic China) and the forerunner of almost every other member of the group.
360
361With its primitiveness, ''Psittacosaurus'' resembles anything but a ''Triceratops'': small (6 ft long), relatively slender, with only hints of horns and frill, this dinosaur looks more like an ornithopod than a ceratopsian externally. Once thought to be capable of walking on all fours, detailed study of its four-fingered forelimbs shows it was entirely bipedal. The main trait revealing its relationship with ''Triceratops'' and kin is the parrot-like upper bill made by a unique bone called "rostral bone", the anatomical hallmark of all ceratopsians. The hook-bill gives it the name “Psittacosaurus”: “psittacus” is Greek for parrot. Another thing that ties ''Psittacosaurus'' with its horned descendants are the prominent bony “cheeks”, far less developed than those of a ''Protoceratops'' but absent in all ornithopods. The shape of the psittacosaur's short head, one of the shortest among all dinosaurs, with a big powerful beak, high orbits and nostrils, and no true frill or horns, makes the resemblance of its face with that of a modern macaw very close. Its body was robust, its tail short and its forelimbs long, much more like ''Leptoceratops'' than a small ornithopod like ''Hypsilophodon''.
362
363''Psittacosaurus'' was discovered in the 1920s in Mongolia together with ''Protoceratops''. Its discoverer was famed paleontologist Roy Chapman Andrews. Since then, psittacosaurs have been discovered everywhere in eastern Asia, from Siberia to China to Thailand, but it was recognized as a basal ceratopsian only in the 1970s: it was believed an ornithopod before because of its body frame reminding a miniature short-tailed iguanodontian. Its fossil record is extremely rich, on the same level of ''Protoceratops'' -- individuals of all ages are known, and also several nests full of eggs. Our “parrot-dinosaur” also detains the record of the non-avian dinosaur with the most species described: more than 10! The most classic one is ''P. mongoliensis'', "Mongolian parrot lizard".
364
365In the 2000s, many new discoveries have further raised the psittaco's importance, making it perhaps the most scientifically well-known member of the whole non-bird 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 purposes (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 were 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, or at least in the protoceratopsians. Another unexpected discovery at the same site debunked the classic “[[MeekMesozoicMammal Mesozoic mammals were underdogs ruled by dinos]]”: the cat-sized carnivorous mammal ''[[http://en.wikipedia.org/wiki/Repenomamus Repenomamus]]'' was found with ''[[EatsBabies baby]]'' [[EatsBabies Psittacosaurus]] ''[[EatsBabies remains]]'' [[EatsBabies in its ribcage]].
366
367In 2016, the "psittaco"'s scales were discovered to have preserved pigments in them, revealing it to be a counter-shaded dark brown on top and a lighter brown on the bottom, like a deer or an antelope. This resulted in modellers building what many news sites bragged to be [[https://upload.wikimedia.org/wikipedia/commons/3/32/Psittacosaurus_model.jpg the most accurate non-avian dinosaur model of all time]].
368
369# '''Entry Time:''' 2000s
370# '''TropeMaker:''' the fossil discoveries from that period
371
372!! Other ceratopsians
373
374Sorry, these aren't here. If you're looking for ''Albertaceratops'', ''Archaeoceratops'', ''Auroraceratops'', ''Avaceratops'', ''Bagaceratops'', ''Chaoyangsaurus'', ''Einiosaurus'', ''Kosmoceratops'', ''Montanoceratops'', ''Yinlong'', ''Zuniceratops'', and others, see [[UsefulNotes/PrehistoricLifeCeratopsids here]]. And [[UsefulNotes/PrehistoricLifeCeratopsidPredecessors here]].
375
376[[/folder]]
377
378[[folder:Pachycephalosaurians]]
379
380Unlike ceratopsians, pachycephalosaurians kept the original bipedal body plan, but evolved thick skull roofs and bony knobs on their heads most likely used for headbutting and display. Due to their unusual teeth, there is the possibility that were partly omnivorous. Needless to say, the iconic member of the group is also the biggest one, ''Pachycephalosaurus''; smaller kinds include ''Stegoceras'', ''Homalocephale'', ''Prenocephale'', "Stygimoloch", and "Dracorex" (the latest two might simply be juveniles of ''Pachycephalosaurus''; see below for more).
381
382!! Thick Spiky Head: ''[[http://en.wikipedia.org/wiki/Pachycephalosaurus Pachycephalosaurus]]'', "Stygimoloch" & "Dracorex" **
383[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/pachy_-_copia_1484.jpeg]]
384[[caption-width-right:350:[[http://pilsator.deviantart.com Wyoming's Thick-Headed Lizard]]]]
385
386''Pachycephalosaurus'' lived during the Late Cretaceous 68-66 million years ago in North America alongside many well-known dinosaurs, like ''T. rex'' and ''Triceratops''. 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 -- scientists once tended to classify all ornithischians that were not stegosaurs, ankylosaurs, and ceratopsians in the ornithopod group: for example, the ceratopsian ''Psittacosaurus'', the basal ''Heterodontosaurus'' and ''Lesothosaurus'', and even the quadrupedal thyreophoran ''Scelidosaurus'' -- its affinity with ceratopsians was demonstrated only in the 1980s.
387
388''Pachycephalosaurus'' (pronounced "pAcky-sEfalo-[=SAURus=]"; "-kEfalo-" is OK too) means "thick-headed lizard", and is by far the biggest known pachycephalosaur, but it's still small compared to most stock ornithischian dinosaurs. Its actual length is uncertain: popular books often set its size at up to 30ft/9m, but a length of 15-18ft/4.6-5.5m is more likely. All of its relatives were no longer than 10 ft. Described in 1931 from a single skull, it was initially identified as ''Troodon'' because the ''Troodon'' was at the time known only from one tooth, which is similar to some pachycephalosaur teeth, and was renamed ''Pachycephalosaurus'' only in 1943. No other parts of the body have been found since then: reconstructions are typically based on smaller pachycephalosaurians, especially ''Stegoceras'', the most complete pachy to date.
389
390''Pachycephalosaurus wyomingensis'', the only known species (possibly; see below), owes its name to Wyoming. This dinosaur is distinguished by its dome-like head, which makes it look very [[MyBrainIsBig 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', making its nickname "The Boneheaded Dino" quite accurate. A number of bony knobs and blunt spikes around the base of the dome and on its nose contrast with the smoothness of the dome to create a look of partial baldness or a monk's tonsure, i.e. a "Roman tonsure"; hence the epithet "[[Myth/RobinHood Friar Tuck]]-osaurus" in ''Film/TheLostWorldJurassicPark'' film. These knobs and spikes were homologous to those on the head and frill of the ceratopsians.
391
392Being 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 may have occasionally eaten insects and small vertebrates as a dietary supplement in the same way many herbivores do today. 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 since the former being larger than the latter, its body might have had an overall stockier frame. Maybe the body of ''Pachycephalosaurus'' was more similar to the robust body of ''Psittacosaurus'' than to the slim body of ''Stegoceras''.
393
394As one of the most recent groups of dinosaurs identified in formal dinosaur classification, pachys never appear in the oldest works. The ur-example was the 1956 novel ''A Gun for a Dinosaur'', but one of the most popular ones was ''WesternAnimation/TheLandBeforeTime'' in 1988, where the pachy shows up as an aggressive creature trying to kill one of the protagonists with headbutts. The headbutting is [[HeadButtingPachy 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. Pachycephalosaurs have often been compared with rams: some scientists even hypothesized they lived in mountain habitats just like the bighorn sheep as an explanation for their rarity in the fossil record (mountains do not preserve fossils well). However, the mountain-living hypothesis is not much followed today, as pachycephalosaurian remains have been found mixed together with the other Late Cretaceous dinosaurs.
395
396In the 2000s, scientists found that the smooth domes of the pachys' skulls would have slipped if they struck against each other, and proposed that pachycephalosaurians bashed each other's sides and hips instead. But even this has been disputed, as additional studies seemed to show that their necks were weaker than traditionally thought, maybe not able to withstand such an impact. This led some scientists to think pachycephalosaurs simply used their dome heads to display maturity like an oversized toucan bill. But a 2013 study found healed injuries in multiple pachycephalosaur domes, suggesting that they were used for headbutting and/or flankbutting after all. This was further supported by computer models demonstrating that the skulls of pachys could withstand much higher levels of force than previously thought, over 1500 pounds or the same amount as two NFL players slamming into each other. This doesn't rule out display entirely however; the the domes were made of a unique fibrous tissue that could have supported brightly colored skin when alive. This same tissue also allowed for quick healing from injuries sustained in fights.
397
398The large ''Pachycephalosaurus'' was once the only "bonehead" portrayed in fiction. This changed in the 2000s when two smaller relatives, "Stygimoloch" and "Dracorex" started making occasional appearances as well, thanks to their [[RuleOfCool even spikier heads]]. These two North American pachycephalosaurian genera have gained quite striking names: ''Stygimoloch spinifer'' and ''Dracorex hogwartsia''. The former means "Spiny Devil from the River Styx", the latter "[[Franchise/HarryPotter Hogwarts]]' Dragon King". Both lived in the USA alongside ''Pachycephalosaurus'' and, like most pachys, are known only from one skull or little more. "Stygimoloch" was discovered in TheEighties: it was Stegoceras-sized and is the only known pachycephalosaur with spikes that developed into true ''horns'', with its dome being tall and narrow (one synonym of it was "Stenotholus", "narrow head"). Meanwhile, "Dracorex" was found only in 2006: it was of similar size, had an almost-as-spiky skull coupled this time with a flat, dome-less head.
399
400But in 2009, it was suggested that these two horned pachys were just juvenile ''Pachycephalosaurus'', as not only are all three from the same time and place, but "Stygi" and "Draco" are only known from juveniles whereas "Pachy" is only known from adults. The idea was that the “devil” and the “dragon” represent the subadult and immature growth stages of the fully mature ''Pachycephalosaurus''. Others have thought ''Pachycephalosaurus'' proper and "Stygimoloch" are males of different age, and "Dracorex" a young female, basing upon the flat head. While the idea of ''Dracorex'' being a juvenile "Pachy" has more or less been fully accepted, "Stygimoloch" still has its supporters, with a few even suggesting it to be a second species of ''Pachycephalosaurus'', ''P. spinifer'', as "Stygi" is known from younger rocks than ''P. wyomingensis''. It may even represent its evolved descendant, in the same way ''Triceratops'' comes in the earlier ''horridus'' and later ''prorsus'' forms (one may also be reminded to the ''Triceratops''-''Torosaurus'' debacle that started just a year later in 2010). This wouldn't be the first time a differences between the adults and juveniles of a dinosaur led people to believe they were different genera; ''T. rex'' was originally thought to have a pygmy relative called ''Nanotyrannus'' until it turned out young ''T. rex''es were just built different from the adults.
401
402Anyway, "Stygimoloch spinifer" did get a memorable scene in ''Film/JurassicWorldFallenKingdom''; it's worth noting that film consultant Jack Horner advised against featuring the "Stygi" due to the above controversy, but was overruled by the filmmakers. But its first apparition in cinema is in 2000's Disney's ''WesternAnimation/{{Dinosaur}}''. "Dracorex hogwartsia", meanwhile, is one of the few real nonbird dinosaurs portrayed in the TV series ''Series/{{Primeval}}'', even though in a [[ArtisticLicensePaleontology quite fanciful way]], with an [[DinosaursAreDragons actual dragon-like crest]] on its back. ''Pachycephalosaurus'' also showed up in the second season of ''Series/PrehistoricPlanet'', using its famous dome to show off to rivals before engaging in a fight that's equal parts headbutting and flankbutting. The episode ends with the showrunners [[ShownTheirWork explaining how the current evidence suggests]] that the animal did indeed butt heads in the manner depicted.
403
404# '''Entry Time:''' 1956 (''Pachycephalosaurus''); 2000 ("Stygimoloch"); 2006 ("Dracorex")
405# '''TropeMaker:''' The novel ''A Gun for a Dinosaur'' (''Pachycephalosaurus''); Disney's ''WesternAnimation/{{Dinosaur}}'' ("Stygimoloch"); ''Series/{{Primeval}}'' ("Dracorex")
406
407!! The Other Stego: ''[[http://en.wikipedia.org/wiki/Stegoceras Stegoceras]]'' *
408
409RuleOfCool is merciless. 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 the stock-role in the pop-consciousness. ''Stegoceras'' matches perfectly with all this, being the most abundant, complete, well-known, and even the first discovered dinosaur within its group by far. At 2.5 m long, ''Stegoceras'' ("horned roof", because its dome was first mistaken for the base of a horn) 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''. Its full scientific name is ''Stegoceras validum'' (validum = courageous).
410
411Both pachys lived in Late Cretaceous North America, but the smaller one was slightly earlier, as usual among Late Cretaceous dinosaurs. It was discovered in year 1924, but was originally thought a weird ornithopod (some even thought the bulge-head was a deformity due to illness); the placement in the current group was made just after the discovery of ''Pachycephalosaurus'' twenty years later. As a pachy, “the other Stego” was a small, two-legged animal with a heavy head and the “body armor” limited to its skull. Some alleged ''Stegoceras'' remains were once putatively announced in China, but they are now thought to pertain to other dinosaurs. Some have also speculated that the ''Stegoceras'' was sexually dimorphic, and one putatively female skull with a slightly less-thick skull-roof was once assigned to its own genus, "Ornatotholus" ("ornated dome").
412
413"[[RunningGag The other Stego]]" also has 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 completeness, to the point of being used as a model for the rest of its group: when you see the body, legs, arms, neck and tail of a pachycephalosaur in a book or movie, you’re arguably watching those of ''Stegoceras''. In dinosaur books, "[[OverlyLongGag the other Stego]]" is often treated as the effective stock pachycephalosaur, unlike TV programs which will [[RuleOfCool prefer the namesake of the family]]. For info about its possible lifestyle, see ''Pachycephalosaurus'' above.
414
415# '''Entry Time:''' 1956
416# '''TropeMaker:''' The novel ''A Gun for a Dinosaur'' (indirectly, as the model for the pachycephalosaurs' body)
417
418!! Dome-Head and Flat-Head: ''[[http://en.wikipedia.org/wiki/Prenocephale Prenocephale]]'' & ''[[http://en.wikipedia.org/wiki/Homalocephale Homalocephale]]'' *
419
420Pachycephalosaurs are very rare things. Few species have been described so far, all from the Late Cretaceous,[[note]]Alleged pachycephalosaurians from the Jurassic and Early Cretaceous, such as ''Ferganocephale'' and ''Yaverlandia'', have all turned out to be from other groups of dinosaurs.[[/note]] and they are all either North American, or Asian[[note]]The Malagasy theropod ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Majungasaurus]]'' was once identified as a pachycephalosaur called "Majungatholus"[[/note]]. While the North American ones are more spectacular (''Pachycephalosaurus''), or more abundant (''Stegoceras''), the Asian ones are nonetheless very interesting; the two most classic ones were both discovered in the 1970s in Mongolia. Their names make a sort of pun if pronounced together: ''Prenocephale'' and ''Homalocephale''. ''Prenocephale prenes'' aptly means “prominent head”; it was very similar to ''Stegoceras'', size included, but had a shorter snout, different tubercles, and a higher dome. Like most boneheaded dinosaurs, only skull material is known, but its first skull is so well preserved that ''even osseous canals'' for the passage of blood vessels are distinguishable! Some alleged ''Prenocephale'' remains were also found in North America, but these now go by different names, like ''Sphaerotholus'' and ''Foraminacephale''.
421
422Pachycephalosaurians used to be divided into two main families, Pachycephalosauridae (those with domed heads) and Homalocephalidae (the ones with flat heads). A third less-known family from the Late Jurassic, Chaoyangsauridae, is now known to be [[UsefulNotes/PrehistoricLifeCeratopsidPredecessors the most basal of the ceratopsian lineage]]. Today, this distinction is not recognized anymore: the flat-headed kinds are actually identical to the bulge-headed ones except for the shape of their skull, and now one single family of pachycephalosaurs is recognized, Pachycephalosauridae. The traditionally most-known "flathead" among the pachys is ''Homalocephale calathocercos''. ''Homalocephale'' was similar to ''Stegoceras'' in size and shape, and is known from several pieces of its skeleton other than the skull, but not complete remains.
423
424The name ''Homalocephale'' means ''flat head'', and with reason: it has indeed [[ExactlyWhatItSaysOnTheTin a flat head]], making it very unpachycephalosaur-looking, rather similar at a first glance to a ''Hypsilophodon''. Actually, its skull structure was clearly pachycephalosaurian, with a slightly thickened skull-roof and bony tubercles very similar to those of ''Prenocephale''. It seems this unusual skull was not adapted for headbutting, but rather for head-shoving, with males simply pushing against each other in contests of strength. Much like with "Dracorex" and ''Pachycephalosaurus'', the similarities to ''Prenocephale'' have led to the hypothesis that ''Homalocephale'' just the juvenile form of the former, with a not-yet developed dome, especially since they lived in the same time and place. However, the existence of juvenile specimens of ''Prenocephale'' suggest otherwise.
425
426The unusual wideness of the ''Homalocephale'' pelvis has also led to speculation about possible viviparity (aka giving birth to ''live'' offspring). There is no proof of this, as well as in every other non-avian dinosaur: remember that modern dinosaurs (birds) and their closest relatives (crocs and turtles) are ''all egg-laying'' animals, while live-bearers among the modern Amniotes are known only from therian mammals (placentals and marsupials) and some lizards and snakes.
427
428# '''Entry Time:''' undetermined
429# '''TropeMaker:''' ''Series/DinosaurPlanet'' (''Prenocephale''); its status as "the flat-headed pachy" (''Homalocephale'')
430
431!! Other pachycephalosaurians
432
433Sorry, these aren't here. If you're looking for ''Goyocephale'', ''Tylocephale'', ''Alaskacephale'', ''Sinocephale'', ''Gravitholus'', ''Sphaerotholus'', ''Wannanosaurus'', ''Micropachycephalosaurus'', ''Yaverlandia'', and others, see [[UsefulNotes/PrehistoricLifePachycephalosaurs here]].
434[[/folder]]
435
436----
437
438!Bipedal plant-eaters (usually)
439
440The [[http://en.wikipedia.org/wiki/Ornithopod Ornithopod]] group contains several ornithischian dinosaurs of different size, from the Middle Jurassic to the Late Cretaceous. The smallest ones were slender, completely bipedal, and possibly omnivorous. The more evolved ones became bigger and returned to 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 the theropods. Unlike the latter, they had small mouth openings and blunt teeth for grinding plant matter. Ornithopods are the most abundant dinosaurs in the fossil record, and as such [[SocialOrnithopod are often portrayed as inoffensive herd-living animals akin to deer and antelope]]. Even though they lacked the thick defenses of the armored ornithischians mentioned above, they made up for that with either speed or sheer bulk.
441
442[[folder:Hadrosaurs]]
443
444[[http://en.wikipedia.org/wiki/Hadrosauridae Hadrosaurs]] are nicknamed "duck-billed dinosaurs" because of their wide, flat beaks, especially evident in some species, but 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 many developed complex prominences above their skulls with social functions.
445
446A comparatively high number of hadrosaur species are portrayed in popular media: ''Parasaurolophus'' and ''Corythosaurus'' thanks to their evident headgears; ''Edmontosaurus'' (called "Trachodon", "Anatosaurus", or "Anatotitan" 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 seldom, ''Saurolophus'', ''Kritosaurus'' & ''Gryposaurus'', ''Lambeosaurus'', and the official archetype of the group, ''Hadrosaurus''. Breaking the usual rule, none of them is the biggest known hadrosaur. ''Hypacrosaurus'', ''Tsintaosaurus'', and ''Shantungosaurus'' are rather common in documentary media, while ''Parasaurolophus'' and ''Edmontosaurus'' have always contended for the record of the most iconic duckbill.
447
448!! An Instrument for Trumpeting: ''[[http://en.wikipedia.org/wiki/Parasaurolophus Parasaurolophus]]'' ***
449[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/parasaur_-_copia_6865.png]]
450[[caption-width-right:350:[[http://tomozaurus.deviantart.com/art/Parasaurolophus-lines-revised-400843441 Walker's Almost Saurolophus]]]]
451
45225-30ft/8-10m 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 not ending in a whip-like shape, a small "hump" on its shoulders, a short but flexible neck with many short vertebrae like a bird (unlike the long but rigid neck of sauropods), and the classic "duck-billed" head, although the "bill" was not as flat and wide as in other relatives. It lived 76 to 73 million years ago in Late Cretaceous North America. . Its long, backwards-pointing protrusion made its skull a bit longer than an adult human’s height. Even though it is often called a "horn", it was actually an extension of the nasal cavities, and ended in a blunt point. Of course, you can often expect to see "paras" in media with the crest looking like a literal horn. Its striking crest makes ''Parasaurolophus'' one of the most popular hadrosaurs, if ''the'' most popular. Significantly, ''Parasaurolophus''[='=] remains are rarer than other duckbills. There are usually three species recognized: ''P. walkeri'' (the classic one), ''P. tubicen'' (tubicen = trumpet player), and ''P. cyrtocristatus'' (meaning "short-crested"). ''P. tubicen'' is the largest of the three and ''P. cyrtocristatus'' has both the smallest body size and smallest crest of the bunch, with both being found in Utah and New Mexico. ''P. walkeri'' was almost identical to ''P. tubicen'', except it lived in Alberta, was a tad smaller, and had longer, more slender crest.
453
454The hadrosaurs' lack of specific weapons has led to them being nicknamed "the Cretaceous Antelopes". They are usually shown in dino-books and documentaries as the "chosen prey" for tyrannosaurs, "raptors", and giant crocodiles, incapable of offering resistance and obliged to flee away from them. This might be TruthInTelevision, but in RealLife "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.
455
456Like the [[AquaticSauropods sauropods]], hadrosaurs were associated with [[AquaticHadrosaurs water]] in pre-Renaissance times. Indeed, the sauropods and the hadrosaurs were once considered the two amphibian lineages of dinosaurs -- all the other dinosaurs were considered adapted for a land-living style. Why? Because 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 -- not because they were thought too heavy to sustain their bulk on land, unlike the giant sauropods. [[ScienceMarchesOn 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, and their duck-like qualities are often played up (see the tellingly-named Ducky from ''WesternAnimation/TheLandBeforeTime'').
457
458Even after it was established that hadrosaurs were mainly terrestrial, scientists still said they were more skilled swimmers than most other dinosaurs and would flee into the water to escape the less able giant theropods. Later research seems to indicate that hadrosaurs were no more accomplished swimmers than any other dinosaurs were, and that tyrannosaurs were probably just as capable of swimming as any other land animal was (ostriches can swim pretty well, and they don't have arms for paddling). Really, a lot of the bias regarding hadrosaurs as being exceptional swimmers or semi-aquatic has to do with the fact they are nicknamed "duckbills", naturally leading many to think of them in comparison to modern-day waterfowl.
459
460Specifically regarding ''Parasaurolophus'', [[WildMassGuessing countless hypotheses]] have been made about the function of its "horn": among them, a tool to thread its way through dense forest foliage, or 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 the sound box of an instrument. Scientists have even been able to ''reproduce'' [[https://www.youtube.com/watch?v=QtpSOpUDCb8 these calls]], which quite resemble a brass instrument -- HilariousInHindsight, this’d really make its crest like a "horn": the ''musical'' one. 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.
461
462This dinosaur has appeared in almost every dino-film, but usually in minor roles -- basically with the sole purpose of increasing the variety of the "dinosaur world". And don’t expect to hear its name, either -- even though it's not one of the shortest dino-names, it remains cool-sounding anyway. A good example is in the ''Franchise/JurassicPark'' films. Some ''Parasaurolophus'' are visible behind the ''Brachiosaurus'' in the famous "Welcome to Jurassic Park!" scene of the first film; they are also seen in every following sequel, too. But all these were simple cameos, and the animal is never named in dialogue - one character does make an attempt in the second movie, but gives up fairly quickly. Other unnamed appearances are in Disney movies -- ''WesternAnimation/{{Fantasia}}'' (where they have the old upright pose and a huge flap of skin between the crest and the neck) and ''WesternAnimation/{{Dinosaur}}'' (where they are more modern-looking). One rare example of a major-character ''Parasaurolophus'' is seen in ''WesternAnimation/TheLandBeforeTime''... at least, Ducky and her parents are officially labeled as such: they’re actually based on its distant relative ''Saurolophus''.
463
464# '''Entry Time:''' 1940
465# '''TropeMaker:''' ''WesternAnimation/{{Fantasia}}''
466
467!! Donald Duckosaur: The ''[[http://en.wikipedia.org/wiki/Edmontosaurus Edmontosaurus]]'' / "Trachodon" / "Anatosaurus" / "Anatotitan" Case ***
468[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/edmontosaur_-_copia_7594.jpeg]]
469[[caption-width-right:350:[[http://pilsator.deviantart.com Regal Edmonton Lizard and Connected Edmonton Lizard (or Connected Duck Lizard if they are not the same)]]]]
470
471No other Stock Dinosaur has had such a MindScrew story as ''Edmontosaurus''/''Trachodon''/''Anatosaurus''/''Anatotitan'': the ''Brontosaurus''/''Apatosaurus'' story is nothing in comparison. Here, ScienceMarchesOn to an insane degree, coupled with huge TaxonomicTermConfusion and IHaveManyNames. This hadrosaur roamed North America at the very end of the Cretaceous, 73-66 mya. Three species in two genera were recognized since TheNineties, ''Anatotitan copei'', ''[[https://en.wikipedia.org/wiki/Edmontosaurus_annectens Edmontosaurus annectens]]'', and ''[[https://en.wikipedia.org/wiki/Edmontosaurus_regalis Edmontosaurus regalis]]'', but ''A. copei'' was merged into ''E. annectens'' in 2011. Some claim this makes ''Edmontosaurus'' the only valid name for this dinosaur, while others support the separation of ''E. annectens'' as ''Anatosaurus annectens''. By any name, these creatures were some of the biggest hadrosaurs, reaching up to 12 m long -- as long as ''T. rex'' and a bit heavier than it. Despite this, their size didn't preclude them from being among the rex's favorite prey, with numerous specimens having ''T. rex'' bite marks on them, including several ''healed'' injuries that tell us they survived ''T. rex'' predation attempts. But like modern-day carnivores, it is likely that rex more often attacked the young, sick, injured and dying than the healthy adults. ''T. rex'' would have specifically hunted ''Edmontosaurus/Anatosaurus annectens'', which lived alongside it 68-66 mya, whereas ''Edmontosaurus regalis'' (''Edmontosaurus'' sensu stricto) lived earlier, about 73-70 mya alongside the smaller ''Albertosaurus''. A third currently unnamed species, previously identified as it own dinosaur called ''Ugrunaaluk'', lived in Alaska about 70-68 mya alongside ''Pachyrhinosaurus'' and ''Nanuqsaurus''.
472
473''Edmontosaurus'' is one of the most scientifically known dinosaurs, with more than ''10,000'' known specimens (most other dinosaurs have less than 100 known specimens, but usually much fewer) showing every detail about its life, even diseases like cancer or fractures. The most striking ones are the "petrified mummies" (all of ''E./A. annectens''), which have preserved not only skin prints, but also ''hardened muscles''. If you don't believe us, [[http://en.wikipedia.org/wiki/Trachodon_mummy see]] [[https://en.wikipedia.org/wiki/Edmontosaurus_mummy_SMF_R_4036 them]] [[http://en.wikipedia.org/wiki/Dakota_(fossil) here]]. The third find shows an unexpected thing: hadrosaurs had a much more massive tail than traditionally thought. If this turns out to be true for all dinosaurs, then [[ScienceMarchesOn many classic studies about dinosaur biomechanics should be reviewed]]. For example, hadrosaurs and their kin are often thought mainly quadrupedal, but a heavier tail would make their center of gravity just under their hips, perfectly balancing their body on two legs. Maybe hadrosaurs mainly walked on two feet and walked on all fours only when grazing, drinking or resting, like kangaroos -- a possible proof of this is that most hadrosaur and iguanodont tracks seemingly do not show prints of forelimbs. Interestingly, Mummy #3 also tells us hadrosaurs were much faster than previously thought, up to speeds of 45km/hr.
474
475''Edmontosaurus/Anatosaurus annectens'' deserves the "duck-billed dinosaur" title more than any other hadrosaur, with its very flat head and spatula-like beak. ''Edmontosaurus regalis'' (''Edmontosaurus'' sensu stricto) had a stockier head and an undulating-edged upper bill, but was still more duckish than most relatives. Their WesternAnimation/DonaldDuck-like face made these dinosaurs unusually nice-looking, making consequently [[{{Narm}} ridiculous]] their possible portrayal in fiction as [[DinosaursAreDragons dragonlike monsters]] -- resulting more similar to [[NightmareRetardant giant]] [[MixAndMatchCritter duck-lizards]]. In popular works, their "duckness" may even be strongly exaggerated, rendering its flat bill literally identical to a duck's, without any teeth or cheeks. In RealLife, hadrosaurs were not exactly toothless. Behind their bill, they had up to ''[[MoreTeethThanTheOsmondFamily a thousand]]'' teeth closely packed together in "batteries" and able to grind the toughest vegetation (fossil pine needles have been found in the aforementioned mummies), giving them the highest number of teeth for any land vertebrate that has ever lived.
476
477Maybe these hadrosaurs had a flap of inflatable skin on their nose to amplify their calls, but this is only a supposition popularized by dino-books. Traditionally both species of ''Edmontosaurus'' have been considered the crest-less hadrosaurs par excellence, because their skull didn't show any bony prominence; but [[ScienceMarchesOn science marched on]] in 2013 and a specimen of ''Edmontosaurus regalis'' was [[http://phenomena.nationalgeographic.com/2013/12/12/surpise-well-studied-dinosaur-actually-had-a-cocks-comb/ discovered to have had a small, fleshy cockscomb on its head]]; this thing was discovered only thanks to the petrified soft tissues found -- maybe other "crestless" dinosaurs had some sort of fleshy protrusions on their head. After all, a chicken skeleton doesn't show sign of their fleshy crest and appendages. However, we're still not sure if ''Edmontosaurus/Anatosaurus annectens'' had the same crest, so most reconstructions forgo it to further differentiate it from ''E. regalis''.
478
479Here’s a brief summary of ''Edmontosaurus''' awesome taxonomic tangle. The first remains, isolated teeth found in the 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 found by Edward Cope were named ''Trachodon [[NamedAfterSomebodyFamous 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'' ("regalis"= royal). In year 1942, one scientist found that ''Trachodon'' could 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'' to ''Edmontosaurus annectens'' ("swimming Edmonton's lizard"). At this point the ''copei'' was the only remaining ''Anatosaurus'', but... taxonomic rules say "''Anatosaurus''" should indicate only the ''annectens''. This meant it should be renamed, too. Since scientists are often very nostalgic, they decided to recall it with a similar name: ''Anatotitan'' ("giant duck"). And then in 2011, ''Anatotitan'' was determined to be a fully grown ''Edmontosaurus annectens'' and thus sunk into ''Edmontosaurus''[[note]]Compare to the ''Dracorex''/''Stygimoloch''/''Pachycephalosaurus'' and ''Triceratops''/''Torosaurus'' stories above[[/note]]. And that leaves us in the present with just the younger, larger ''Edmontosaurusa annectens'' and the older, smaller ''Edmontosaurus regalis'', although some scientists suggest the former should become ''Anatosaurus annectens'' again. [[SarcasmMode Quite simple, isn’t it?]]
480
481"Trachodon" first appeared in pop-media in 1925 (''Film/TheLostWorld'' film adaptation), in which it's portrayed as prey for a giant carnivore. After that, it became THE duckbill in the public consciousness, to the point where "trachodont" was also used as a popular synonym of "hadrosaur" (a bit like how "brontosaur" is sometimes used to refer to any kind of sauropod). After 1990 however, "Trachodon" rapidly disappeared from pop-consciousness -- although its ghost is still seen from time to time. Meanwhile, "Anatosaurus" experienced a surge in popularity during the Dino-Renaissance and became the most widely-used name in pop-culture until the '90s popularized "Anatotitan", mainly thanks to ''Series/WalkingWithDinosaurs'' (which acknowledged the possibility of it being the same as ''Edmontosaurus annectens'' in the companion book some 10 years before it was proven true). But after "Anatotitan" was sunk into ''Edmontosaurus annectens'', ''Edmontosaurus'' has been growing in popularity, albeit primarily in docu-media. "Anatotitan" and "Anatosaurus" still appear semi-regularly though, with the latter being used in ''VideoGame/{{Saurian}}'' as an informal name for ''E. annectens''.
482
483That said, ''Edmontosaurus'' hasn’t gone an especially long way in non-documentary media: when ''Edmontosaurus'' appears, it's simply known as a "duckbill," and the crested ''Parasaurolophus'' has become the most portrayed hadrosaur in fiction today (probably because of the crest and the less convoluted backstory). ''Edmontosaurus/Anatosaurus annectens'' is also ''much'' more common in documentaries than ''Edmontosaurus regalis'', and for good reason: With the possible exception of ''Hypacrosaurus'' (see below), ''E./A. annectens'' is the only hadrosaur known from the same time and place as ''Tyrannosaurus'', ''Triceratops'', and the other famous dinosaurs from the end of the Cretaceous. Therefore, if a work is showing the end of the Cretaceous and wants to be accurate, this is usually the hadrosaur they'll use. ''E. regalis'' tends to show up much more in popular dino-books by contrast. Additionally, the unnamed Alaskan ''Edmontosaurus'' we briefly brought up at the start has shown up in the ''Film/WalkingWithDinosaurs'' movie and ''WesternAnimation/MarchOfTheDinosaurs'', albeit mostly identified with ''E. regalis''.
484
485# '''Entry Time:''' 1925
486# '''TropeMaker:''' ''Film/TheLostWorld'' (film)
487
488!! The Good-Mother: ''[[http://en.wikipedia.org/wiki/Maiasaura Maiasaura]]'' **
489
490This hadrosaur deserves a special mention. The same size as ''Parasaurolophus'' and contemporary to it, 76-74 mya, ''Maiasaura'' did not have the striking headgear of it (only a small relief above the eyes), nor did it have such a wide bill like ''Edmontosaurus''. Nonetheless, it has been one of the most important dino-finds ever.
491
492Hundreds of ''Maiasaura''s were discovered together in Montana in 1980 by famous paleontologist [[http://en.wikipedia.org/wiki/Jack_Horner_(paleontologist) Jack Horner]] (better known as the ''Franchise/JurassicPark'' official consultant, and also for having defended against colleagues the unpopular "scavenging T. rex" theory in some TV appearances), 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!
493
494Before the 1980s, only a few dinosaurian eggs were known to science: those of ''Protoceratops'', oviraptorids, "Hypselosaurus", ''Psittacosaurus'', and a few others, 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 themselves? ''Here'' is the proof of parental care: only adult ''Maiasaura'' could have fed the young such plant matter until they grew large enough to finally leave their nest. Horner gave a MeaningfulName to his caring dinosaur: ''Maiasaura peeblesorum'' means "Peebles' good mother lizard" (note the unusual feminine suffix ''-saura''). It was his deep study of this dinosaur and its parenting habits that gave Horner his prestige in the scientific community.
495
496Horner and other scientists have since made a possible reconstruction of the ''Maiasaura'' lifestyle. [[SocialOrnithopod Huge herds of possibly up to 10,000 individuals]] used to migrate across Western North America from Canada to Montana for wintering at their nesting islands. 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 (adult ''Maiasaura'' were too heavy to sit on their eggs like modern chickens do.) After the hatching, adults fed their helpless babies good food, moved by their cute appearance: the babies’ skulls show large eyes and short muzzles like modern mammal cubs. After developing their skeletons, the youngsters started to search for food on their own; finally, the whole herd undertook again their migration once more. In short, an overall behaviour ''very'' similar to many modern migrating birds.
497
498This reconstruction made the top of the Dinosaur Renaissance, definitively debunking the old [[DumbDinos big, stupid, unfeeling, oafs]] thing, and making ''Maiasaura'' just as common in popular books as ''Parasaurolophus'' and ''Edmontosaurus''. However, ''Maiasaura''s inconspicuous appearance was [[RuleOfCool not interesting enough]] to earn it any movie appearances. Even though the "good mother dinosaur" and the whole argument around are often mentioned in the first ''Franchise/JurassicPark'' novel (which, by the way, had Horner as the consultant), this was totally overlooked in Creator/StevenSpielberg's following film. However, ''Maiasaura''s impact was still felt across other dinosaur portrayals. In ''WesternAnimation/TheLandBeforeTime'' for instance, all the herbivorous dinosaurs migrate through the lands and hatch their young in crater-like nests made of earth. In reality, evidence suggests some dinosaur groups, like the sauropods, did not take care of their young at all, and other would have likely practiced different styles of parenting. However, our knowledge of dinosaur parenting in most groups is still incomplete and a lot of their behaviors remain speculative.
499
500In TheNewTens, ''Maiasaura'' finally made its first movie appearance in the Japanese animated movie ''Anime/YouAreUmasou'' 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, a bit like the songbirds that adopt unwillingly cuckoo chicks. Before that, the ''Maiasaura'' had also appeared on teleivison in ''Series/DinosaurPlanet'' (as one of the protagonists alongside the tyrannosaur ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Daspletosaurus]]''), as well as an episode of ''WesternAnimation/TheMagicSchoolBus'' (as one of the dinosaurs encountered by Ms. Frizzle and her students on a TimeTravel field trip to Late Cretaceous North America).
501
502# '''Entry Time:''' 1990
503# '''TropeMaker:''' ''Literature/JurassicPark'' (the first book)
504
505!! Big Round Crest: ''[[http://en.wikipedia.org/wiki/Corythosaurus Corythosaurus]]'' **
506
507Hadrosaurs were very diverse. Even though they all shared the same body-plan, their heads were ''wildly'' different between species. They are divided in two main lineages: the lambeosaurines (those with hollow crests, like ''Parasaurolphus'') and the saurolophines (those without, such as ''Edmontosaurus'' and ''Maiasaura''). Other than ''Parasaurolophus'', the only lambeosaurine with a significant number of appearances in pop-media is ''Corythosaurus''. Naturally, the latter has been a rarer sight. In the ''Franchise/JurassicPark'' film series, ''Corythosaurus'' joins ''Parasaurolophus'' only in the third film. And just like ''Parasaurolophus'', good luck ever hearing ''Corythosaurus'' get named in fiction. 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.
508
509''Corythosaurus'' was slightly smaller than ''Parasaurolophus'' (7-9 m long), and lived in Late Cretaceous North America about 77-75 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 (68-66 mya), this makes a slight AnachronismStew case. More accurate works might depict these two animals being menaced by smaller, earlier tyrannosaurids like ''Daspletosaurus'' or ''Gorgosaurus''.
510
511First discovered in 1912 by Barnum Brown (who is also known for having found the very first ''Tyrannosaurus'' skeletons in Montana about a decade earlier), the "corytho", unlike the "para", has one of the richest fossil records among hadrosaurs. Several complete specimens are known to science, including many juveniles. The corythosaur’s cranial structure was similar to the parasaur's, with a relatively narrow duckbill compared with ''Edmontosaurus'' and expanded nasal bones that formed a crest. However, the ''Corythosaurus'' crest was very different than that of ''Parasaurolophus'': it was laterally-flattened, round-shaped, and put upright above the head. Its shape has often been compared to a Greek helmet or to the crest of the cassowary bird (''Corythosaurus'' just means "helmet lizard"; its full name, ''C. casuarius'', means "cassowary-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 to be both very different-sized and very 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. In fact, these differences initially led scientists to believe them to all be different genera of dinosaurs under such names.
512
513Issues 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 proper comparison. Since hadrosaurian crests are so differently-shaped, experts have concluded that they also had the function of visually distinguishing 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 youngsters. Just as French horns and bassoons have a different timbre, so would ''Corythosaurus'' and ''Parasaurolophus''.
514
515# '''Entry Time:''' 1940
516# '''TropeMaker:''' ''WesternAnimation/{{Fantasia}}''
517
518!! Giant Hadrosaurs: ''[[http://en.wikipedia.org/wiki/Lambeosaurus Lambeosaurus]]'' & ''[[http://en.wikipedia.org/wiki/Shantungosaurus Shantungosaurus]]'' *
519
520A frequently ignored fact about hadrosaurs was that they were the biggest plant-eating non-sauropodian dinosaurs. The most massive species were taller, longer and heavier than even the largest 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 one was the record-holder?
521
522Traditionally, two hadrosaurs have contended for the record: the crested North American ''Lambeosaurus'' (namesake of the lambeosaurines) and crestless Chinese saurolophine ''Shantungosaurus''. ''Lambeosaurus'' ("Lawrence Lambe's lizard"), one of the most striking-looking hadrosaurs, also has a rich fossil record, with two distinct species described. A third species was originally described, but was reclassified in 2012 as a brand new genus, ''[[http://en.wikipedia.org/wiki/Magnapaulia Magnapaulia]]''.
523
524Overall, ''Lambeosaurus'' was similar to ''Corythosaurus'' with a flat, vertical crest with the same hollow spaces. However, the crest of the best 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 a 90° angle 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 slightly forwards like a pomapadour. ''Magnapaulia laticaudus'' (formerly "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, nearly twice the weight of a large ''Tyrannosaurus rex'' like the famous Sue. In contrast, the two confirmed species of ''Lambeosaurus'' were “only” 10 m long and weighing 4/5 tons, the same size as most hadrosaurs. Significantly, the normal-sized ''Lambeosaurus''es have classically been [[RuleOfCool oversized in books, to match]] ''Magnapaulia''.
525
526Discovered in the 1970s, ''Shantungosaurus giganteus'' ("gigantic Shandong lizard", from the Chinese province it was first found) was quite similar to ''Edmontosaurus'', and usually believed closely related with it. However, it was bigger than the latter, the same size of the aforementioned "giant lambeosaur" ''Magnapaulia'' (15m/50ft long and 12 tons or more in weight). Despite the fact that they rivalled certain sauropods in size, neither hadrosaur has received any attention in fiction yet, although they are staples of dino-books. Both subfamilies of duckbills, the lambeosaurines and saurolophines, have members both in Asia and in North-America -- giving more proof of a connection between the two landmasses in the Late Cretaceous over what is now the Bering Strait.
527
528# '''Entry Time:''' 1990s (''Lambeosaurus''); undetermined for ''Shantungosaurus''
529# '''TropeMaker:''' ''Literature/{{Dinotopia}}'' (''Lambeosaurus''); its status as the biggest hadrosaur (''Shantungosaurus'')
530
531!! USA and China make Peace: ''[[http://en.wikipedia.org/wiki/Saurolophus Saurolophus]]'' *
532
533In general, Late Cretaceous dinosaurs in Western North America are very similar to those in Eastern Asia. This is because these landmasses were joined at the time by a stripe of dryland where the Bering Strait is today. This means that dinosaurs at the time could wander from one continent to another. But even though many groups of dinosaurs are shared between both continents (pachycephalosaurians, ornithomimosaurs, oviraptorosaurs, tyrannosaurids, ankylosaurids, and ceratopsians, to name a few), Asian and North American dinosaurs are usually classified as distinct genera: see ''Tyrannosaurus rex'' and ''Tarbosaurus bataar'' for example.
534
535But there is 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 many more specimens were discovered in the Gobi Desert 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'' ("narrow-beaked crested lizard"), still remains today the most abundant duckbill from Asia.
536
537However, the North American species, ''Saurolophus osborni'' ("Osborn's crested lizard") has also been important. 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, curved upwards instead of downwards, and ''really was'' horn-shaped; but as a saurolophine, the crest of ''Saurolophus'' made by solid bone and not hollow like that of the ''Parasaurolophus''. And if you're wondering about the name, yes, ''Saurolophus'' was the namesake of the saurolophines.
538
539The two “horned” duckbills tend to be confused with each other by non-specialists -- and their similar names don’t exactly help to resolve the mix-up. The main example is seen in ''WesternAnimation/TheLandBeforeTime'': Ducky, the hadrosaurian member of the FiveManBand of dinosaurs, has a clearly ''Saurolophus''-like crest, and yet has been labeled a ''Parasaurolophus''. Ironically, as a saurolophine, ''Saurolophus'' was closer to ''crestless'' hadrosaurs like ''Edmontosaurus'' than to ''Parasaurolophus''! Also of interest is that ''Saurolophus'' and its kin have often been depicted in paleo-art with a speculative, inflatable, frog-like air-sac on its snout, although there is no hard proof for this. This air-sac was conceived as a mean to amplify sounds just like the hollow crests of ''Corythosaurus'' and ''Parasaurolophus''.
540
541# '''Entry Time:''' 1988
542# '''TropeMaker:''' ''WesternAnimation/TheLandBeforeTime'' (identified as ''Parasaurolophus'')
543
544!! Taxonomy Confusions: ''[[http://en.wikipedia.org/wiki/Hypacrosaurus Hypacrosaurus]]'' & ''[[http://en.wikipedia.org/wiki/Tsintaosaurus Tsintaosaurus]]'' *
545
546If you see a “frisbee”-crested hadrosaur in books or documentaries, don't assume it’s ''Corythosaurus''. The latter had a "twin" called ''Hypacrosaurus altispinus'', with a similar crest though fairly smaller, wider, and pointed on the top. Sadly, since some (possibly female) ''Corythosaurus'' also have a rather low crest, this doesn’t help us so much to differentiate the two; the surest trait to do it is to spot the taller neural spines of ''Hypacrosaurus'' in a mount (''altispinus'' means "tall-spined"). Not surprisingly, ''Hypacrosaurus'' has been confused with ''Corythosaurus'' or even ''Lambeosaurus'' in the past, and to complicate matters, some juvenile remains from these three animals were even labeled as two genera on their own, "Cheneosaurus" and "Procheneosaurus"!
547
548''Hypacrosaurus'' was, notably, the last of the lambeosaurines to live in North America, with its most recent fossils dating back to the time just before ''T. rex'' and ''Triceratops'' showed upon the scene. So while it may not have been around to be hunted by the rex, it did coexist with dinosaurs like ''Anchiceratops'', ''Arrhinoceratops'', ''Pachyrhinosaurus'', (see the ceratopsians folder above) and the previously mentioned ''Edmontosaurus regalis'' and ''Saurolophus'' -- all preyed upon by ''Albertosaurus''. That being said, some very ''Hypacrosaurus''-like remains have been found in the Ojo Alamo formation dating back to the very end of the Cretaceous 66 million years ago, suggesting that it or a close relative may have survived all the way up to the mass extinction. In the nineties, a nidification site in North America full of ''Hypacrosaurus'' nests and hatchlings has been discovered, similar to ''Maiasaura''; this find has made ''Hypacrosaurus'' a much more well-understood duckbill among scientists.
549
550Nicknamed the “unicorn dinosaur”, the lambeosaurine ''Tsintaosaurus spinorhinus'' ("spiny-nosed Tsing-Tao lizard") was found in the 1940s by famed Chinese paleontologist Yang Chung-chien (or C.C. Young) like the sauropod ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Mamenchisaurus]]'', and thus is one of the “classic” Chinese dinosaurs.
551
552Few other dinosaurs have had such a tormented ScienceMarchesOn story like that of ''Tsintaosaurus''. It was initially described from fragmentary remains that seemed to show a single horn-like crest pointing forward and upward upon its head like a unicorn's horn. Said crest was often shown with [[DoesThisRemindYouOfAnything a pair of small speculative airsacs at the base of its long, thin, rod-shaped crest]]. Then, scientists took the crest away in the 1990s, thinking it was actually a misplaced piece from the rest of its skull, with some even hypothesizing that ''Tsintaosaurus'' was the same as another lesser-known Asian duckbill, the crestless saurolophine ''[[http://en.wikipedia.org/wiki/Tanius Tanius]]''. However, a later find to show that ''Tsintaosaurus'' really did have a crest... until a 2013 study showed the "horn" was just a fragment from a ''backwards''-pointing crest, looking a bit like that of its also-Asian relative ''[[UsefulNotes/PrehistoricLifeHadrosaurs Olorotitan]]'' but more elongated.
553
554# '''Entry Time:''' the 1990s
555# '''TropeMaker:''' the issues about their crests
556
557!! The Decayed Nobleman: ''[[http://en.wikipedia.org/wiki/Kritosaurus Kritosaurus]]'' & ''[[http://en.wikipedia.org/wiki/Gryposaurus Gryposaurus]]'' *
558
559Most of the North American hadrosaurs were described at the beginning of the 20th century, in the second memorable “Dino-Rush” led in North America. Among them, one of the most historically relevant has been the saurolophine ''Kritosaurus'', found in New Mexico (most of the others were found in Alberta). Other than the skull, saurolophines and lambeosaurines were distinct in other ways: the neural spines of the latter were taller, and their ornithischian backward-pointing pubis was more rounded at the tip.
560
561In old books, ''Kritosaurus'' 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 [[FiveManBand Five Hadrosaur Band]]. This “band” has also appeared once in cinema: in 1940, the “Rite of Spring” of ''WesternAnimation/{{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. The classic species of ''Kritosaurus'' is ''K. navajovius'', after the Navajo people.
562
563Then, ScienceMarchesOn hit hard on this duckbill. In the 1990s, additional specimens from Alberta were reclassified as ''Gryposaurus'' (which had been previously sunk into ''Kritosaurus'' after its initial description in the 1910s), taking with them the best skull material showing the classic bulge that once pertained to the kritosaur. To worsen things, the genus ''Kritosaurus'' has revealed to be a wastebasket taxon, and most of its former remains are either now of uncertain attribution or considered new dinosaurs like ''Anasazisaurus'' or ''Naashoibitosaurus'' -- some labelled "K. australis" in the 70s were found in an unusual location for duckbills, South America, and now go by ''Huallasaurus''. While ''Kritosaurus'' remains a valid genus today, it has now become poorly understood just like ''Hadrosaurus'' (below), and we even don’t know if the kritosaur really had the classic bump on its nose. Nowadays, ''Gryposaurus'', the new owner of the skulls previously attributed to ''Kritosaurus'', has, in a sense, taken the heritage of the “decayed nobleman" ''Kritosaurus'', becoming the new “bulge-nosed hadrosaur” in popular portrayals.
564
565# '''Entry Time:''' 1940 (''Kritosaurus''); 1990s (''Gryposaurus'')
566# '''TropeMaker:''' ''WesternAnimation/{{Fantasia}}'' (''Kritosaurus''/''Gryposaurus'')
567
568!! The First-known U.S. Dinosaur: ''[[http://en.wikipedia.org/wiki/Hadrosaurus Hadrosaurus]]'' *
569
570Surprise! “Hadrosaur” not only means one precise group of related dinosaurs, it also indicates a single genus of duckbill: ''Hadrosaurus foulkii''. But its importance is almost entirely historical.
571
572''Hadrosaurus'' was the very first dinosaur ever identified as such in North America (and outside of 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”. Oddly for a US dinosaur, it was found in New Jersey -- dinosaur remains are extremely rare east of the Mississippi. However, dino discoveries in the States began on the East Coast, and it was only with the start of the Bone Wars - sometimes called the Great Dinosaur Rush - that the American West become more important.
573
574''Hadrosaurus foulkii'' (William Foulke was the one who first found its bones) was already recognized as an ''Iguanodon'' relative, but the latter was still depicted as totally quadrupedal at the time. ''Hadrosaurus'' remains, though very incomplete, clearly showed an at least partly ''bipedal'' creature. Joseph Leidy (its namer and the so-called father of American paleontology) was the first paleontologist to have described a large-sized dinosaur in the classic upright posture: a revolutionary idea at the time that only became more popular later.
575
576''Hadrosaurus'' also has the distinction of being the first dinosaur ever mounted in a museum; however, the original bipedal posture [[ScienceMarchesOn has changed from upright to horizontal since the 1970s]]. Sadly, ''Hadrosaurus''' skull was practically unknown, so Leidy didn’t understand that he was 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''. ''Hadrosaurus'' was originally believed to be a saurolophine, and at the time, the group was known as "hadrosaurines" after it, but later studies revealed it to be a much more primitive animal outside of the two subfamilies and instead near the base of the hadrosaurid family tree - this in turn led to the "hadrosaurines" being renamed the saurolophines.
577
578''Hadrosaurus'' was the animal originally chosen by Michael Crichton for the "stampede scene" in his original ''Franchise/JurassicPark'' novel, while Spielberg's following film chose to substitute it with the ornithomimosaur ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Gallimimus]]''. ''Hadrosaurus'' is occasionally confused with ''Edmontosaurus'' in popular non-fictional representations due to their superficial similarities, but you can also sometimes hear the ''Hadrosaurus'' name being used in pop culture for all hadrosaurs as a result of confusion between the specific animal ''Hadrosaurus'' and the general term "hadrosaur".
579
580# '''Entry Time:''' 1990
581# '''TropeMaker:''' The ''Literature/JurassicPark'' novel
582
583!! Other hadrosaurs
584
585Sorry, these ones aren't here. If you're looking for ''Prosaurolophus'', ''Secernosaurus'', ''Brachylophosaurus'', ''Amurosaurus'', ''Olorotitan'', ''Charonosaurus'', ''Telmatosaurus'', ''Tethyshadros'', ''Velafrons'', ''Claosaurus'', ''Mandschurosaurus'', and others, see [[UsefulNotes/PrehistoricLifeHadrosaurs here]].
586
587[[/folder]]
588
589[[folder:Hadrosaur Predecessors]]
590
591There 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. Both were from Early Cretaceous Europe. And if you're even luckier you might see the Late Jurassic ''Camptosaurus'', ''Dryosaurus'', and ''Nanosaurus'', the first similar to ''Iguanodon'' and the other two to ''Hypsilophodon''. Also worthy of note are ''Tenontosaurus'' and ''Ouranosaurus'' because are they are strongly associated with one famous predatory dinosaur each (''Deinonychus'' and ''Spinosaurus'' respectively; albeit for different reasons). ''Muttaburrasaurus'' and ''Leaellynasaura '' are known for being rare examples of Australian dinosaurs, while ''Thescelosaurus'' and ''Orodromeus'' are the animals that the controversial "petrified heart" and "petrified nests" were attributed to, respectively. ''Heterodontosaurus'', ''Lesothosaurus'', ''Fabrosaurus'', and ''Scutellosaurus'' are here for convenience, but are not true ornithopods anymore according to modern knowledge. ''Iguanodon'', ''Camptosaurus'', ''Dryosaurus'', ''Tenontosaurus'', ''Muttaburrasaurus'', and ''Ouranosaurus'' are all part of a group of ornithopods known as the iguanodontians, which include the ancestors of the hadrosaurs. Meanwhile, ''Hypsilophodon'', ''Leaellynasaura'', ''Orodromeus'', ''Thescelosaurus'' and tiny ''Nanosaurus'' once formed a group called the "hypsilophodonts", but are now considered to be a miscellany of extremely primitive ornithopods or even basal ornithschians and not true ornithopods at all.
592
593!! The Veteran of the Dinosaurs: ''[[http://en.wikipedia.org/wiki/Iguanodon Iguanodon]]'' ***
594[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/iguanodon_-_copia_1718.jpeg]]
595[[caption-width-right:350:[[http://pilsator.deviantart.com Bernissart's Iguana Tooth]]. ]]
596
597Living 126 to 122 million years ago in Early Cretaceous Europe, this is one of the most iconic non-avian dinosaurs from the "old continent" together with ''Compsognathus'', ''Plateosaurus'', ''Megalosaurus'', ''Baryonyx'', and to an extent, ''Archaeopteryx''. It’s also one of the most scientifically well-known dinosaurs, and one of the most abundant in the fossil record. ''Iguanodon'' has had a special role within the stock dino ensemble. Along with ''Megalosaurus'' and ''Hylaeosaurus'', it’s the only dinosaur that has covered the whole history of scientific and popular portraits, but unlike the rarely-portrayed-these-days megalosaur and hylaeosaur, ''Iguanodon'' is still pretty common today in pop culture.
598
599Although nearly as big as ''Tyrannosaurus'' (10 m or more, and up to 4 tons), ''Iguanodon'' was not an especially striking-looking dinosaur. Being an earlier relative of hadrosaurs and possibly their ancestor, its shape resembled one of the latter, with three-toed hindfeet, a flexible neck (but less so than hadrosaurs), a long muscular tail stiffened by bony tendons, a massive body, and hindlimbs longer and stronger than forelimbs. Non-hadrosaurian traits include: the backbone not being curved at the shoulder level; grinding teeth much less numerous and put in one single row on each half-jaw like almost all non-hadrosaur dinosaurs; a totally crest-less, bump-less head; and a deep, narrow beak very unlike the duck-billed one.
600
601Unlike the hadrosaurs, ''Iguanodon'''s most distinctive traits are in its hands, not its head. The best known of these is the [[HookHand spiked thumb]], made of the first digit's phalanxes fused together and encapsulated in a horny sheath, usually shown in books as a weak weapon against enemies. It also had a very flexible, opposable "pinkie" finger, maybe to grasp vegetation. Hadrosaurs too had a little-finger in their hands other than the three main digits, but it was smaller than the ''Iguanodon'''s one and maybe useless and vestigial. Like hadrosaurs, the three central fingers of ''Iguanodon'' were fused together in a hoof-like structure and supported the weight of the dinosaur when on four legs, though incorrect freely-fingered iguanodonts and hadrosaurs often appear in portrayals.
602
603We don’t know for sure if iguanodonts and hadrosaurs were mainly tree-browsers or ground-grazers. However, classic portraits usually show iguanodonts in the usual "tripodal" stance and browsing like a giraffe. Some paleoart has also added a long extendable giraffe-like tongue to reach tree foliage, but this is unlikely. In these old portraits, ''Iguanodon'' was substantially the reptilian equivalent of the giant ground sloth ''[[UsefulNotes/StockDinosaursNonDinosaurs Megatherium]]'', also often portrayed as an upright tree-browser with a horsey head, robust clawed forelimbs, a giraffe-like tongue, and a tail used as a tripod together with the hindlegs.
604
605''Iguanodon'' is one of the three animals (along with ''Megalosaurus'' and ''Hylaeosaurus')' called "dinosaurs" for the first time in history (1842), by the famous English paleontologist [[http://en.wikipedia.org/wiki/Richard_Owen Sir 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 an official name. It was initially described from its iguana-like teeth and a few other incomplete remains: hence its name meaning ''iguana's tooth''. But then, in 1877 [[SocialOrnithopod about 40]] ''Iguanodon'' skeletons were discovered within a coal mine in Belgium near the town of Bernissart, the very first "dino graveyard" ever found. These remains were named ''Iguanodon bernissartensis'' and described by Belgian zoologist Louis Dollo. Many other remains were later assigned to ''Iguanodon'', often found outside Europe and across the full timespan of the Jurassic and Cretaceous. Most have since been split in other genera, making it a wastebasket taxon much like the more classic "Megalosaurus wastebasket". Among these genera include ''Hypselospinus'', ''Dakotadon'', ''Altirhinus'', ''Cumnoria'', ''Mochlodon'', and ''Mantellisaurus'', the last of which was named after Gideon Mantell.
606
607Most dinosaurs have changed their look at least once: ''Iguanodon'' has done this ''twice''. The first attempt at reconstruction showed [[http://www.places-to-go.org.uk/crystal_palace_iguanodon.htm a huge dragon-like quadruped]], and one of its thumbspikes was inaccurately put on its nose -- an understandable mistake, given the very fragmentary nature of its original remains. The life-sized ''Iguanodon'', alongside ''Megalosaurus'', ''Hylaeosaurus'', and other extinct animals (including Ice Age megafauna, marine reptiles, and pterosaurs), were sculpted by Benjamin Waterhouse Hawkings and shown to the public during the 1856 Universal Exposition in London, at the famous Crystal Palace. A banquet was organized to celebrate the event... inside the still incomplete iguanodon model! Even though the palace was ultimately destroyed by a fire, the sculptures survived, and the Art/CrystalPalaceDinosaurs are still there for all to see.
608
609After the discovery of the complete skeletons from the Belgan "dinosaur mine" in the 1870s, the ''Iguanodon'' became [[https://youtu.be/pQJIVxzIUic 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 1970s and led by English paleontologist David Norman made Iguanodon quadrupedal again (though still capable of standing and running on two legs), with cheeks hiding the teeth in the living animal.[[note]]Once, all ornithischian dinosaurs were portrayed with no cheeks and a wide mouth running from ear to ear, like saurischian dinosaurs: this was based on modern reptiles, which are invariably cheek-less. The shape of ornithischian jaws showed they could have had cheeks to store plant matter during mastication, like modern herbivorous mammals. Thwas is confirmed by the "hadrosaur mummies." If alive today, an ornithischian’s head would resemble a hairless [[MixAndMatchCritter ungulate with a beak]].[[/note]] An excellent example of this new portrait is seen in Disney's ''WesternAnimation/{{Dinosaur}}'', which made ''Iguanodon'' the main character in the story -- [[ExecutiveMeddling exaggerating its horse-like look]] with fleshy lips instead of the proper bill, and showing it always on all fours like an actual horse.
610
611Even though it has been extremely common in dinosaur books and other non-fictional media, ''Iguanodon'' did not make any significative apparitions in cinema or TV before Disney's ''WesternAnimation/{{Dinosaur}}'' and ''Series/WalkingWithDinosaurs'' were broadcast during the [[TurnOfTheMillennium 20th-21st century change]]. The most recent one is in 2022's ''[[Film/JurassicWorldDominion Jurassic World Dominion]]''. RuleOfCool easily explains why: with its generic look and weak weapons, it doesn’t bear comparison with ''UsefulNotes/TyrannosaurusRex'' jaws, ''[[TemperCeratops Triceratops]]'' horns, ''[[ToughArmoredDinosaur Stegosaurus or Ankylosaurus]]'' armour and weaponized tails, "[[RaptorAttack raptor]]" claws, or the immense size of [[GentleGiantSauropod sauropods]] -- and some portraits could even leave the beak or the thumbspikes substituting them with a lizard-head and generic hands, making it even more inconspicuous. However, its historical and scientific importance remain in dino fans' consciousness, as no other dinosaur has run the whole two centuries of popular portraits: from [[https://nixillustration.com/science-illustration/2022/retro-vs-modern-02-iguanodon/ Crystal Palace rhinos, to giant two-legged iguanas, up to Disneyfied horses]].
612
613# '''Entry Time:''' 1854
614# '''TropeMaker:''' Art/CrystalPalaceDinosaurs
615
616!! Tree-Climber or Ground-Runner?: ''[[http://en.wikipedia.org/wiki/Hypsilophodon Hypsilophodon]]'' **
617
618When we think about small bipedal dinosaurs, our mind automatically comes to guys like the “raptors”, the “compies”, the ornithomimids, or the oviraptorids, all theropods. 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''.
619
620One of the first dinosaurs discovered, way back in 1849, it 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, [[SocialOrnithopod dozens of complete individuals have been found]], and this also explains its historical role as the stock small ornithopod. Most remains come from England, especially the southern Isle of Wight, home of many other Early Cretaceous English dinosaurs, but some uncertain remains attributed to ''Hypsilophodon'' come from North America and Spain.
621
622A very small dinosaur, 2 m long or less, the bulk of a large dog, ''Hypsilophodon foxii'' ("Fox's high-crested tooth") 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 (but also smaller teeth on the tip of the upper jaw, a primitive trait among ornithischians), hands with five digits (coelurosaurs never have more than three fingers) and a rounder belly to contain the typical large gut of a herbivore.
623
624''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 quickest-running dinosaurs. If alive today, it would probably appear one of the cutest-looking dinos, maybe even suitable as a [[KidsLoveDinosaurs household pet]].
625
626Before the 1970s, ''Hypsilophodon'' was believed to be 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 sometimes even fiction. This is how it is shown, for example, in ''WesternAnimation/{{Fantasia}}''-- the tiny, green tree-climbing dinosaurs that the ''Stegosaurus'' disturbs are ''Hypsilophodon''. Few other dinosaurs have had such a great ScienceMarchesOn story: maybe only ''Spinosaurus'', ''Megalosaurus'' and ''Iguanodon'' can rival it in this area. While ''Iguanodon'' was often reconstructed using a classical kangaroo as a model, ''Hypsilophodon'' was often compared with the tree kangaroo.
627
628In the rare event this little critter is portrayed in Fictionland, expect it to be portrayed as the dinosaurian RedShirt, little more than a bite-sized snacklet for the big hungry carnivores. This portrayal can be shared with small theropods as well, especially the toothless ones. Hypsilophodonts are often cited with ornithomimids as examples of harmless dinos: ostrich-dinosaurs too had a graceful appearance, large eyes, and were fast runners, but are more strongly associated with birds in public mind than the small ornithopods like ''Hypsilophodon'' (and were also closely related to them). A singular case is in ''[[WesternAnimation/TheLandBeforeTimeIIITheTimeOfTheGreatGiving The Land Before Time 3]]'', in which the leading villain of the story is a strange-looking puppy of ''Hypsilophodon'' named [[ALizardNamedLiz Hyp]] who is the leader of a TerribleTrio of young dino-rivals to the protagonistic FiveManBand.
629
630''Hypsilophodon'' has always been quite common in paleo-art and dino-books; for example, the portrayal made by John Sibbick 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 further paleo-artistic depictions of "hypsies". As the picture was from 1985, the animal is shown scaly; today many scientists think it was covered by feather-like structures, like other small ornithischians.
631
632# '''Entry Time:''' 1940
633# '''TropeMaker:''' ''WesternAnimation/{{Fantasia}}''
634
635!! The Wildebeest of the Jurassic: ''[[http://en.wikipedia.org/wiki/Camptosaurus Camptosaurus]]'' *
636
637Let’s face it: it’s RuleOfCool that undisputedly dominates when coping with dinosaurs. ''Camptosaurus'' is the perfect example. This is one of the most abundant dinosaurs in the 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 ''Franchise/JurassicPark'' book, in which the boy Tim brings his father to a natural science museum and the first dinosaur skeleton they see belongs to a juvenile ''Camptosaurus''. But when was the last time you saw it in documentaries other than ''Series/PlanetDinosaur'', which portrays it as a simple fodder for the allosaurs?
638
639''Camptosaurus'' lived in Late Jurassic North America just alongside ''Brontosaurus'', ''Diplodocus'', ''Brachiosaurus'', ''Stegosaurus'', and indeed ''Allosaurus'': it could have shown up in ''Series/WalkingWithDinosaurs'', ''Series/TheBalladOfBigAl'', or even ''WesternAnimation/WhenDinosaursRoamedAmerica''. Maybe its rather generic appearance (by dinosaur standards, of course) was judged as too inconspicuous to capture the watchers’ interest. Other two very important Late Jurassic North American dinosaurs unfairly missed by the ''Walking with...'' series are the sauropod ''Camarasaurus'' and the theropod ''Ceratosaurus'', both at least appearing in WDRA.
640
641''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 ''Iguanodon'' and the hadrosaurs: indeed, ''Camptosaurus'' was one of the most primitive big ornithopods and one of the most basal thumb-spiked iguanodontians (properly known as [[http://en.wikipedia.org/wiki/Ankylopollexia ankylopollexians]], meaning "hooked thumbs"). In the Jurassic world still dominated by sauropods, camptosaurids and stegosaurians were the only big ornithischians that were successful, anticipating the great diversity bird-hipped dinosaurs reached later in the Cretaceous.
642
643The most known ''Camptosaurus'' species is ''Camptosaurus dispar''; other alleged ''Camptosaurus''es found in Europe (Portugal and England) have been given their own genera, like ''Draconyx'' and ''Callovosaurus''. It could have fallen prey to ''Ceratosaurus'' and ''Allosaurus'': but a fully-grown, 7m/20ft long ''Camptosaurus'', the same length of a 1-ton ''Ceratosaurus'' but heavier than it, 2 tons, could have defended itself against it like a wildebeest or a zebra can against predators smaller than a lion.
644
645# '''Entry Time''': 1990s
646# '''TropeMaker''': ''Literature/JurassicPark'' novel
647
648!! The Gazelles of the Jurassic: ''[[http://en.wikipedia.org/wiki/Dryosaurus Dryosaurus]]'' & ''[[http://en.wikipedia.org/wiki/Nanosaurus Nanosaurus]]'' *
649
650The 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 that ''Camptosaurus'' didn't, all made around the TurnOfTheMillennium, though with very minor roles -- in one case, it serves only as prey to ''Allosaurus'' -- but it doesn't appear in ''Series/PlanetDinosaur''.
651
652''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 upper beak other than the lower, and lacking the forth reversed toe of ''Hypsilophodon'' and (ironically) the closer-to-''Iguanodon'' ''Camptosaurus''. Like the camptosaur, ''Dryosaurus'' was actually a basal iguanodontian and not related to ''Hypsilophodon'', and the prototype of its own lineage, the Dryosaurids. It was [[ScienceMarchesOn once]] considered a big "hypsilophodont", as big as the Late Cretaceous ''Thescelosaurus'', but "hypsoliphodont" is no longer considered an actual group, rather a motley collection of miscellaneous small ornithopods and basal ornithischians.
653
654Both 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'' -- but have since been re-classified as their own dinosaur, ''[[http://en.wikipedia.org/wiki/Dysalotosaurus Dysalotosaurus]]''. Other alleged ''Dryosaurus'' were found in Early Cretaceous Europe, but now go by ''Valdosaurus''.
655
656''Camptosaurus'' and ''Dryosaurus'' are very frequently portrayed in dinosaur books, especially the former; here both are typically shown as among the favorite prey of ''Allosaurus'' and ''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 on two legs as fast as they could. Dryosaurids, being smaller and more maneuverable, were probably faster than camptosaurids, but the latter, being bigger and stronger, had more chances to defend themselves effectively against their predators. Both dryosaurs and camptosaurs were herd animals, as shown by the numerous individuals found together in fossil sites.
657
658Also in Late Jurassic USA, alongside ''Camptosaurus'' the Wildebeest and ''Dryosaurus'' the Gazelle, we have ''[[RuleOfThree Nanosaurus]]'' the Dik-Dik. Meaning "dwarf lizard", this was indeed a very small animal, 1.5 m long (smaller than an ''Hypsilophodon''), with a very convoluted ScienceMarchesOn story on par with that of ''Edmontosaurus''. Discovered in 1877 during Cope’s and Marsh’s “Bone Wars”, ''Nanosaurus agilis'' ("agile dwarf lizard") was very commonly portrayed in old textbooks for having detained the record of “the smallest North American dinosaur” for almost a century. But in the 1970s, its validity was called into question due to the fragmentary nature of its remains. Also in the 1970s, a similar animal, ''Othnielia rex'', was described from the same sites, only to be renamed in 2007 as ''Othnielosaurus consors'' (both names derived from Othniel Charles Marsh) after many of the remains were reassigned to another dinosaur called ''Laosaurus celers''. Additionally, in 1990, a fourth dinosaur from the same habitat was named ''Drinker nisti'', after Marsh's rival Edward Drinker Cope! Finally, in 2018, newly discovered and better quality fossil material revealed ''Othnielia'', ''Laosaurus'', ''Othnieliosaurus'', and ''Drinker'' to all be the same as ''Nanosaurus'', thus taking several dinosaurs all known from a multitude of scrappy materials and merging them into one animal known from a large amount of material while also reviving ''Nanosaurus'' as a valid genus.
659
660Much like ''Camptosaurus'' and ''Dryosaurus'', ''Nanosaurus'' doesn't get a lot of spotlight when it comes to Late Jurassic North American dinosaurs; between the ''Walking with...'' series, ''Planet Dinosaur'', and ''When Dinosaurs Roamed America'', it only appears in the first one under the ''Othnielia'' name -- unnamed in the Late Jurassic focus episode and as a background critter in the ''Ballad of Big Al'' special. But also like the two Late Jurassic North American ornithopods, it tends to appear a lot in dinosaur books, usually under the ''Othnielia'' name, making it the most recognized of [[IHaveManyNames all its many names]]. But today, it is no longer considered "the smallest North American dinosaur" -- that record now pertains to a tiny heterodontosaurid found only in 2009, ''[[UsefulNotes/PrehistoricLifePrimitiveOrnithischians Fruitadens]]'', another inhabitant of Late Jurassic North America and a neighbor of the abovementioned ornithopods, as well as the famous sauropods, stegosaurs, and theropods.
661
662# '''Entry Time''': 1999
663# '''TropeMaker''': ''Series/WalkingWithDinosaurs'' and sequels (both)
664
665!! Beware My Long Tail: ''[[http://en.wikipedia.org/wiki/Tenontosaurus Tenontosaurus]]'' *
666
667One of the most iconic scenes in paleo-artistic works made during the 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").
668
669This was one of the most basal known iguanodontians, an Early Cretaceous animal similar in size to the more evolved but earlier ''Camptosaurus''. Unlike the latter, the tenontosaur was totally devoid of thumbspikes, being more basal than the ankylopollexian iguanodontians (just like ''Dryosaurus'' was). And also like the dryosaur, it was [[ScienceMarchesOn once considered]] an overgrown "hypsilophodont" -- more precisely, the biggest member of the group by far. It had long front limbs (classic portrayals often show it quadrupedal) with five digits each, a long neck, a small head, and the primitive four-fingered hindfeet of basal ornithopods, but its most distinctive trait was surely its tail. Its tail was much longer than in 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 diplodocid sauropod -- but it could have actually been more rigid than often shown.
670
671First found in the 1970s in Montana, the first tenontosaur skeleton was surrounded by several ''Deinonychus'' skeletons. It was just this detail that made John Ostrom consider the idea of these predators as wolf-like pack-hunters capable of bring down larger prey with their agility and their sickle-claws; ''Tenontosaurus'' has thus given indirectly contribute to the modern public image of dinosaurs as fast, intelligent, and dynamic animals.
672
673In these struggles, ''Tenontosaurus'' is usually shown swinging its enormous tail and hitting some “raptors”, 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 RaptorAttack). In fact, since the original ''Tenontosaurus'' discovery, ''20%'' of all tenontosaur fossils have been found in association with ''Deinonychus'' and 14 of the 50 fossil sites ''Tenontosaurus'' is known from have also produced ''Deinonychus'' remains. And on ''Deinonychus''' side, only ''6'' ''Deinonychus'' fossil sites lack ''Tenontosaurus''. Clearly, there was some kind of predator-prey relationship between the two.
674
675But as discussed in [[UsefulNotes/StockDinosaursSaurischianDinosaurs our entry on raptors]], the idea that raptors hunted in packs has been called into question by some scientists, who point out that neither birds nor crocodiles do this. Thus, it's been suggested that maybe the ''Dinonychus'' were simply scavenging on the carcass of a ''Tenontosaurus'' they found already dead, with the presence of their skeletons around the herbivore just being of those who were killed in squabbles over the choicest parts -- the same happens today when Komodo dragons gather around a dead water buffalo. Its important to note however that most of the ''Tenontosaurus'' found with ''Deinonychus''remains around them were juveniles, so it seems that ''Deinonychus'', pack-hunter or not, generally avoided fully grown individuals. Adults however would have had to worry about ''Acrocanthosaurus'', the apex predator of the day.
676
677Maybe the first mention of ''Tenontosaurus'' in popular culture is in the first ''Franchise/JurassicPark'' 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 ''Deinonychus'' is the real identity of the chosen raptor in the story. The "tenonto" also appears in ''Series/JurassicFightClub'' as the victim of a pack of ''Deinonychus'', naturally. Finally, ''Tenontosaurus'' is also one of the chosen dinosaurs for TheEighties / TheNineties expo called [[http://en.wikipedia.org/wiki/Dinamation Dinamation]], which showed several animatronic self-moving life-sized puppet-dinosaurs in various museum around the world as a further attraction other than the usual mounted skeletons and painting murals. Here, too, it is shown as the meal for a group of ''Deinonychus''.
678
679# '''Entry Time:''' 1980s
680# '''TropeMaker:''' its role as the chosen prey for ''Deinonychus''
681
682!! The Gazelles of the Cretaceous: ''[[http://en.wikipedia.org/wiki/Thescelosaurus Thescelosaurus]]'' & ''[[http://en.wikipedia.org/wiki/Orodromeus Orodromeus]]'' *
683
684''Hypsilophodon'', ''Dryosaurus'', ''Nanosaurus'', and ''Tenontosaurus'', the three traditionally most-known "hypsilophodonts", were Late Jurassic or Early Cretaceous; but ''Hypsilophodon''-like animals also existed in the Late Cretaceous, even though they tend to be overshadowed in paleo-art by the spectacular ornithischians of their period: hadrosaurs, ceratopsians, ankylosaurs, and pachycephalosaurs. In North America, while duckbills took the “wildebeest” role, the “gazelle” one was mainly played by the thescelosaurids, named after their most famous member of their group, ''Thescelosaurus neglectus''. ''Thescelosaurus'' ("marvelous lizard") was 3-4 m long and lived at the extreme end of the Cretaceous, 68-66 mya, making it a neighbor of ''Tyrannosaurus rex'' and ''Triceratops'' and one of the very few dinosaurs that managed to see the [[RockFallsEveryoneDies asteroid]] at the end of the Dinosaur Era.
685
686Rather similar to ''Dryosaurus'' in appearance, ''Thescelosaurus'' had previously been classified by some as a small basal iguanodontian like ''Dryosaurus'' was, but cladistic research have revealed it instead belonged to its own lineage of dinosaurs. Rather robustly-built if compared with ''Hypsilophodon'', the thescelosaur had some small bony scutes on its back, maybe placed under the skin and not visible in the living animal. Once thought unique to this dinosaur, it has since been found that ''Hypsilophodon'' also possessed these osteoderms, which were arguably for defense.
687
688A ''Thescelosaurus'' specimen nicknamed "Willo" is the animal from which the controversial “fossilized heart” comes from. As exciting as the idea of a preserved dinosaur heart sounds, it is almost certainly a fossilization artifact: that is, a piece of stone that just casually resembles a heart. Discovered in 2000, this stony concretion was celebrated by the media as the ultimate proof of “warm-bloodedness” among dinosaurs, because it seemingly showed a four-chambered heart just like bird and mammals and unlike most modern reptiles -- crocodilians have four-chambered hearts, but their ancestors could have been warm-blooded as hypothesized in the late 2000s.
689
690There were other thescelosaurids from Late Cretaceous North America that were smaller and lived slightly earlier than ''Thescelosaurus''. The most notable of these was ''Orodromeus makelai'', "Makela's runner of the (Egg) Mountain". It was discovered in Montana in 1988 by Jack Horner and his assistant Robert [[ExactlyWhatItSaysOnTheTin Makela]] in the same site in which they had found ''Maiasaura'' eight years before. At their site, Horner and Makela noted some small, unusually spiral-shaped nests full of eggs containing fossilized embryos. To small to be from ''Maiasaura'', they attributed these to ''Orodromeus'', and noted that since the bones inside those eggs were already well-formed, the ''Orodromeus''' hatchlings must have been more independent at birth than the ''Maiasaura'' ones. ScienceMarchesOn however, and later it was found that those eggs/embryos were instead from the theropod ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Stenonychosaurus]]'' (aka ''Troodon''). The ironic thing is that fossils of stenonychosaurs were discovered around those putative ''Orodromeus'' nests, but it was thought that they were actually preying on Orodromeus nestlings: an astonishingly similar story to the “''Oviraptor'' robbing ''Protoceratops'' eggs” tale some six decades earlier. ''Orodromeus'' shows up in ''Series/DinosaurPlanet'' being hunted by ''Stenonychosaurus''-as-''Troodon''.
691
692While not Stock Dinosaurs (or even minor-Stocks), there are some other thescelosaurids we'd like to take note of here. ''[[http://en.wikipedia.org/wiki/Oryctodromeus Oryctodromeus]]'' ("digging runner"), found in 2007 and living quite a bit earlier than the similar-named ''Orodromeus'' (100-94 mya as opposed to 77-75 mya), is notable for showing the first proof of digging behavior among non-avian dinosaurs: its skeleton was found inside a fossilized burrow. A relative found in Alberta known since the start of the 20th century is ''[[http://en.wikipedia.org/wiki/Parksosaurus Parksosaurus]]'' ("William Parks' lizard", sometimes misspelled "''Parkosaurus''"), which was similar in size and shape to ''Orodromeus'' but lived about 70-69 mya. ''[[http://en.wikipedia.org/wiki/Zephyrosaurus Zephyrosaurus]]'' ("lizard of the western wind"), lived earlier than all these, in the Early Cretaceous alongside ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Deinonychus]]'', likely being one of its main prey items.
693
694# '''Entry Time:''' 2000s
695# '''TropeMaker:''' the "heart of stone" (''Thescelosaurus''); ''Series/DinosaurPlanet'' (''Orodromeus'')
696
697!! Duck-billed Spinosaur: ''[[http://en.wikipedia.org/wiki/Ouranosaurus Ouranosaurus]]'' *
698
699Here’s one of the most classically-cited dinosaurian MixAndMatchCritter examples: ''Ouranosaurus'', "brave monitor-lizard" ("ourane" is both the Arabic word for "brave" and the Tuareg name for the Desert Monitor). This medium-sized (7m/20ft long) ornithopod looked like a cross between other more familiar dinosaurs. It had a flat duck-like bill like ''Edmontosaurus''; a small relief on its head like ''Maiasaura''; thumb spikes like ''Iguanodon''; and, most 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 [[UsefulNotes/StockDinosaursNonDinosaurs Dimetrodon]]-like "sail" in popular portraits. The combination of duck-like bill and thumb spikes is explained by the fact that ''Ouranosaurus'' was a sort of in-between of hadrosaurs and ankylopollexian iguanodontians, more derived than ''Iguanodon'' and ''Camptosaurus'' but less so than ''Edmontosaurus'' and ''Parasaurolophus''. Think of it as among the most derived of the iguandontians.
700
701Discovered by a French expedition to Niger led by Philippe Taquet in the 1970s, ''Ouranosaurus [[ExactlyWhatItSaysOnTheTin nigeriensis]]'' lived in what is today the Sahara Desert, just like ''Spinosaurus aegyptiacus'' (which was found a bit further north, ex. [[ExactlyWhatItSaysOnTheTin 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 stegosaurians or the frill of ceratopsians, but like the latter cases, this is unproven. Additionally, we need to consider the fact when these dinosaurs were alive, the Sahara was a lush wetland, with ''Spinosaurus'' being an amphibious fish-eating dinosaur. Like ''Spinosaurus'', some scientists argue that ''Ouranosaurus'' had a fleshy and/or fatty 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 find remains of soft tissues of both dinos, the question will remain unanswered. Interestingly, because of the scarcity of its fossil record (only two individuals were found in the expedition, and nothing more since) some think ''Ouranosaurus'' was more solitary than other ornithopods, averting SocialOrnithopod.
702
703In popular works, the spinosaur has often been shown as the [[RedShirt predator of the ouranosaur]], the latter being smaller and thus a potentially easy prey for it. But [[AnachronismStew this is actually a mistake]], simply because ''Ouranosaurus'' lived 15 million years before ''Spinosaurus'' (there was however a relative of ''Spinosaurus'' living alongside the ouranosaur, that is ''[[UsefulNotes/PrehistoricLifeLargeTheropods Suchomimus]]''; the giant crocodile relative ''Sarcosuchus'' also lived alongside both dinosaurs). Just as an example, the ''Ouranosaurus''' one documentary appearance in ''Series/PlanetDinosaur'' showed the two living at the same time (''Sarcosuchus'' has the same time-travel problem). Here, ouranosaurs appear as herd animals, but as said above, there is no proof of this. Even today, not all deer/antelope species are gregarious like wildebeest or zebras -- for examples, moose and kudus are known to be rather lonely animals.
704
705In 2021 ''Ouranosaurus'' has made its way into fiction, appearing in the third season of ''WesternAnimation/JurassicWorldCampCretaceous''. Here, they are presented as dangerous herd animals, almost like "duck-billed spinosaurs". Before, it is spottable in some of the many sequels to ''WesternAnimation/TheLandBeforeTime'' (''The Great Longneck Migration''), recognizable thanks to its "sail".
706
707# '''Entry Time:''' undetermined
708# '''TropeMaker:''' its "sail" and the association with ''Spinosaurus''
709
710!! Land Down Under Dinosaurs: ''[[http://en.wikipedia.org/wiki/Muttaburrasaurus Muttaburrasaurus]]'' & ''[[http://en.wikipedia.org/wiki/Leaellynasaura Leaellynasaura]]'' *
711
712If you’ve seen the fifth episode of ''Series/WalkingWithDinosaurs'', you’ll already have an idea of who we’re talking about. Many dinosaurs are known today from Africa, from huge ''Giraffatitan'' and ''Carcharodontosaurus'' to smallish ''Massospondylus'' (the most abundant) and ''Kentrosaurus'', to the tiny ornithischians ''Heterodontosaurus'' and ''Lesothosaurus'' (see below for these two). But very few non-bird dinosaurs are known from Australia, even today. Some important dino-fossils were found there in TheEighties, especially four animals: ''Muttaburrasaurus langdoni'', ''Leaellynasaura amicagraphica'', ''Minmi paravertebra'', and the alleged dwarf polar allosaur (based on a single ankle bone now considered too dubious to readily classify), all from Early Cretaceous East Australia. ''Muttaburrasaurus'' is probably the most well-known and portrayed Australian dinosaur in media. Like many Australian fossils, it has a rather odd-sounding name, but this is justified: it comes from Muttaburra, a small village of the Queensland outback. It looked like an undersized ''Iguanodon'', but was much more primitive despite having lived slightly more recently (approx. 112 mya). It had different grinding teeth and the primitive four toes for each foot seen in ''Camptosaurus'': it was once believed to be related to the camptosaur, but is now considered to be one of a group of extremely basal iguanodontians called the rhabdodontomorphs.
713
714About the same size as ''Camptosaurus'', ''Ouranosaurus'' or ''Tenontosaurus'', the muttaburrasaur was visually distinct from all of them, thanks to its defining trait, an evident bulged nose reminiscent of the old portraits of the hadrosaur ''Kritosaurus''. This "big nose" is an unusually specialized trait for a basal iguanodontian like this, making its head more similar externally to that of a Late Cretaceous hadrosaurid than to a camptosaur or tenontosaur. No fossil hands are known from ''Muttaburrasaurus'', but it is typically represented with well-developed thumb-spikes in drawings -- even though their presence is impossible due to its primitiveness. Among the ornithopods we've covered here so far, only ''Tenontosaurus'' is considered more primitive than ''Muttaburrasaurus''; even ''Dryosaurus'' is considered more derived despite it living long before the ''Muttaburrasaurus'' or the ''Tenontosaurus'' did. Thus, ''Muttaburrasaurus'' is considered a late-surviving basal animal, like ''Leaellynasaura'', ''Minmi'', and the giant amphibian ''[[UsefulNotes/PrehistoricLifeOtherExtinctCreatures Koolasuchus]]''. It seems Australian, Antarctic, and (in part) South American fauna remained primitive across the Mesozoic, perhaps until the Great Extinction of 66 mya. Even today, the mammalian fauna of Australia and (in part) of South America is rather peculiar compared with the other continents, while Antarctica has lost it completely when it froze, during the Mammal Age, aka the Cenozoic. This can be attributed to the isolation these continents experienced for much for the Mesozoic and Cenozoic -- something that continues today for Australia's marsupials and monotremes.
715
716''Muttaburrasaurus'' appeared prominently in ''Series/WalkingWithDinosaurs'' in the fifth episode "Spirits of the Ice Forest" as the biggest animal of its fauna and with speculative airsacs on its nose to make loud sounds. It also showed up in the third sequel of ''WesternAnimation/TheLandBeforeTime'' (rather incorrectly portrayed, in truth), together with ''Hypsilophodon'' and ''Nodosaurus'' (see above).
717
718Dinosaur names are often thought of as bizarre-sounding, and ''Leaellynasaura'' certainly does match the commonplace very well, like its bigger compatriot ''Muttaburrasaurus''. ''Leaellynasaura amicagraphica'' was named after the daughter of its discoverers, Leaellyn. A much more obscure Australian dinosaur, ''[[UsefulNotes/PrehistoricLifeBirdlikeTheropods Timimus]]'', was named after Leaellyn's brother, Tim. It has ''mimus'' at the end because was originally thought an ornithomimosaur. ''Leaellynasaura'' (sometimes misspelled "''Leaellynosaura''") owes well its feminine suffix ''saura'', just like the hadrosaur ''Maiasaura'' which means “good-mother lizard”. First found in 1989, ''Leaellynasaura'' was a small (1 m long) bipedal animal similar to ''Hypsilophodon''. Once considered a “hypsilophodont”, the dissolution of this group for its lack of unifying traits except small size had made the classification of this little dinosaur uncertain. Some regard it as a more a more basal ornithischian, but in 2019, it was proposed to be part of a uniquely Southern Hemisphere group of extremely primitive ornithopods known as the [[https://en.wikipedia.org/wiki/Elasmaria Elasmarians]], many of which were also formerly classified as "hypsilophodonts". Fossils discovered in Australia in the 2000s indicate presence of a small Early Cretaceous ornithischian with tail 3 times longer that its own body (even more than the ''Tenontosaurus'' tail); whether this is the same taxon as ''Leaellynasaura'' or not remains to be seen.
719
720The discovery of ''Muttaburrasaurus'', ''Minmi'', and ''Leaellynasaura'' in the 1980s made sensation in Australia, because very few dinosaurs were known before in the LandDownUnder, all fragmentary. ''Muttaburrasaurus'' still is one of the most complete dinosaurs found there; ''Leaellynasaura'' ‘s skeletons are more incomplete, but the latter's importance was due to having contributed to enforce the “warm-blooded dinosaurs” hypothesis even more. In the Early Cretaceous, Australia was not the temperate/tropical/desertic country we know today, but a colder world with warm summers and cold winters, because it was much closer to the South Pole. How could such a small, clearly non-migratory animal like this manage to survive that icy winter? The only explanation was that ''Leaellynasaura'' was warm-blooded. Furthermore, its unusually big eyes could have been used to see throughout the darkness of the polar winter. All these arguments were discussed in ''Series/WalkingWithDinosaurs'', in which a family of ''Leaellynasaura'' are the main characters. The show also portrayed ''Muttaburrasaurus'', as a migrating animal that flees the winter in herd like caribou. And in the years since that show, fossils demonstrating that many small ornithischians possessed feather-like structures have led many to depict ''Leaellynasaura'' with a thick coat of fluff to shield it from the winter.
721
722# '''Entry Time:''' 1999 (both)
723# '''TropeMaker:''' ''Series/WalkingWithDinosaurs'' (both)
724
725!! A Herbivore with Fangs: ''[[http://en.wikipedia.org/wiki/Heterodontosaurus Heterodontosaurus]]'' **
726
727Among basal ornithischian dinosaurs, there were curious things. ''Heterodontosaurus tucki'', for example, might as well be renamed the "[[MixAndMatchCritter boar-bird]]".
728
729The "hetero" lived in the Early Jurassic like the armored ''Scelidosaurus'' but farther south, in South Africa, 200-190 million years ago. ''Heterodontosaurus'' superficially resembled ''Hypsilophodon'' with its slender, bipedal body, but was even smaller (1.2m/4ft long), more robust, and with longer forelimbs. As the namesake and archetype of the [[https://en.wikipedia.org/wiki/Heterodontosauridae heterodontosaurids]], it was actually one of the "largest" basal ornithischians, despite being only a bit bigger than a ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Compsognathus]]''. Its skeletons have not left traces of feather-like structures, but since its close relative ''[[UsefulNotes/PrehistoricLifePrimitiveOrnithischians Tianyulong]]'' had them, it's highly probable that ''Heterodontosaurus'' also had them.
730
731Unlike the ur-tank dinosaur ''Scelidosaurus'', ''Heterodontosaurus'' was discovered only in TheSixties. 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 like a boar; behind, molar-like teeth to grind up tough vegetation, analogous to those seen in more evolved ornithischians; and in front of them, the small peg-like teeth only on the tip of the upper jaw, a typical condition of all basal ornithischians. This makes its head as an odd mix of primitive and evolved traits.
732
733We are not sure about what the "hetero" ate in life, because of this specialized dentition. The dominant hypothesis is that ''Heterodontosaurus'' was a mostly herbivorous omnivore, eating insects to supplement its usual diet of vegetation, while the "fangs" would have been used for display and/or competition, a bit like in male baboons or musk-deer (thus acting more like "tusks"). Some scientists suspect only males had the large canines like what is seen in some small species of deer, but there is no evidence for this. 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.
734
735''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 [[RuleOfCool 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. AnachronismStew and MisplacedWildlife are in play here, since ''Coelophysis'' lived only in Late Triassic North America, while the plateosaur was around in Late Triassic Europe, ''but'' both dinosaurs did have relatives living alongside ''Heterodontosaurus'' in southern Early Jurassic Africa. Some suspect that the heterodontosaur could have defended itself well against enemies thanks to its robust tusks like modern baboons and peccaries do with big cats, but this is not demonstrable due to the lack of fossilized combat like the one between ''Protoceratops'' and ''Velociraptor''.
736
737# '''Entry Time''': undetermined
738# '''TropeMaker''': Its "canine" teeth
739
740!! Tiny Fore-Runners: ''[[http://en.wikipedia.org/wiki/Lesothosaurus Lesothosaurus]]'' & ''[[http://en.wikipedia.org/wiki/Fabrosaurus Fabrosaurus]]'' *
741
742When talking about ornithischians, we can find the same issues as in saurischians: in the Triassic/Early Jurassic they were all so similar to each other that it’s hard task to classify them accurately. Nonetheless, they are extremely important animals for scientists, despite their often-tiny size. Other than the scelidosaurians and the heterodontosaurians (which make two distinct groups on their own), we have some other examples of early ornithschians, among them ''Lesothosaurus''.
743
744''Lesothosaurus diagnosticus'' was once considered the [[{{Pun}} forerunner]] of all bird-hipped dinos, and thought not to belong to any great ornithischian group, but [[ScienceMarchesOn newer research]] suggests that it could in fact be a very basal, armorless thyreophoran, thus the ancestor of scelidosaurians, stegosaurians, and ankylosaurians. From Early Jurassic Southern Africa like ''Heterodontosaurus'', its name derives from [[ExactlyWhatItSaysOnTheTin the Kingdom of Lesotho]], a small South African nation (once called Basutoland) where its remains were dug out in 1978; the species name ''diagnosticus'' underlines its importance to understanding early ornithischian evolution. Fragmentary remains from Lesotho that have been named ''Fabrosaurus australis'' ("Southern Fabre's lizard") may be synonymous with it; even though they were named slightly before ''Lesothosaurus'', in TheSixties, ''Fabrosaurus'' would ''not'' be the valid genus name for this dinosaur, as its fossils are too dubious to be properly classified as a distinctive species (much like what happened with ''Troodon'' and ''Stenonychosaurus'').
745
746In old textbooks, the "fabrosaur" was often shown as the protypical generic-looking basal ornithischian; since the 1980s, ''Lesothosaurus'' took over this role. Once, the "fabrosaurid" family was recognized by scientists as a catch-all grouping for undetermined small ornithischians from Triassic to Early Cretaceous, but modern cladistic science do not accept artificial assemblages like this, and "fabrosaurid" has mostly disappeared in literature. Alleged "fabrosaurids" included also some animals that have also been classified as "hypsilophodonts", like ''Nanosaurus''.
747
748Merely 90cm/3ft long, even smaller than the already-small ''Heterodontosaurus'', and with a more gracile frame, a smaller head, and shorter forelimbs, ''Lesothosaurus'' was about the bulk of a ''Compsognathus'' weighing only 3-4 kg. Unlike the scelidosaurians and the heterodontosaurians, it doesn't seem to have any specialization in its anatomy. Its mouth had simple teeth not apt for proper grinding but only for tearing vegetation just like the contemporaneous prosauropods. It probably had only small "cheeks", but already had the lower toothless bill (technically, the "predental bone") that is the main hallmark of every ornithischian other than the shape of the pelvic bones. Its forelimbs were short and five-digited; its hindlimbs four-digited, birdlike and apt for running; and its tail long and flexible (like ''Heterodontosaurus'', its vertebrae lacked the bony tendons of the more evolved bird-hipped dinos). Finally, its pelvis lacked a "prepubis", the forward-pointing prominence of the pubis typical of most evolved ornithischian lineages (the scelidosaurs and heterodontosaurs also lacked it).
749
750Because 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''. Interestingly, it's also hypothesized that ''Lesothosaurus'' underwent long "hibernations" to survive the harsh desertic conditions of its habitat, but this is not yet demonstrated.
751
752About this dinosaur, there are the same issues as ''Heterodontosaurus'' and ''Scelidosaurus'' in pop-portrayals: it can be shown living alongside Triassic icons ''Plateosaurus'' and ''Coelophysis'' (often as prey for the latter), despite being from the Early Jurassic. Like ''Hypsilophodon'', ''Heterodontosaurus'', or the prosauropod ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Mussaurus]]'', ''Lesothosaurus'' is also usually cited as an example of a particularly small herbivorous dinosaur.
753
754# '''Entry Time:''' undetermined
755# '''TropeMaker:''' Their status as the precursors of the other ornithischians
756
757!! Little-Armored Critter: ''[[http://en.wikipedia.org/wiki/Scutellosaurus Scutellosaurus]]'' *
758
759''Scutellosaurus'' ("lizard with small shields", not to be confused with the Permian reptile ''[[UsefulNotes/StockDinosaursNonDinosaurs Scutosaurus]]'') has traditionally been considered the most primitive thyreophoran, variably classified in the Scelidosaurids or in its own family, Scutellosaurids.
760
761Discovered only in the 1980s, ''Scutellosaurus lawleri'' was a small bipedal animal with a similar look to ''Lesothosaurus'', but it was slightly bigger, longer-tailed, more robustly-built, and with longer forelimbs: some think was partially quadrupedal. More importantly, it had light armor made by small bony plates placed in rows upon its torso, and a row of plates along its backbone from neck to tail: all similar to the armor of the bigger ''Scelidosaurus'', but without the "horns" on its head. Some could say ''Scutellosaurus'' was a bit like a primitive miniature ''Tenontosaurus'' because of its very developed tail, longer than the rest of the body (''Scelidosaurus'' had a more normal-length tail).
762
763Like the scelidosaur, ''Scutellosaurus'' lived in the Early Jurassic, but it was found not in Europe like the former but rather North America, living alongside the popular double-crested ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Dilophosaurus]]'' and the small early land-living crocodile relative ''[[UsefulNotes/PrehistoricLifeNonDinosaurianReptiles Protosuchus]]''. Some portrayals have shown the scutellosaur as the dilophosaur's prey, but this is not confirmed. Despite its small size for dinosaur standards ''Scutellosaurus'' was slightly bigger and heavier than ''Protosuchus'', and the latter arguably hunted only young scutellosaurs. It is unknown if the dinosaur had the same feather-like structures seen in many small ornithischians, but if it had them, they would have been interspersed between the bony scutes that give to it its name.
764
765# '''Entry Time''': undetermined
766# '''TropeMaker''': its armor
767
768!! Other hadrosaur predecessors
769
770Sorry, these aren't here. If you're looking for ''Altirhinus'', ''Mantellisaurus'', ''Callovosaurus'', ''Rhabdodon'', ''Yandusaurus'', ''Pisanosaurus'', ''Technosaurus'', ''Fruitadens'', ''Eocursor'', ''Tianyulong'', ''Kulindadromeus'', and others, see [[UsefulNotes/PrehistoricLifeHadrosaurPredecessors here.]] And [[UsefulNotes/PrehistoricLifePrimitiveOrnithischians here.]]
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