Sauropods include about three hundreds of kinds described so far. Other than the famous Power Trio Apato/Brachio/Diplodocus and the several contenders for "the biggest dinosaur" title, the most common sauropods in documentary-media have been Camarasaurus (mid-sized, short-necked, quite like a middle between an apatosaur and a brachiosaur), Cetiosaurus (a mid-sized, primitive and generic-looking kind from Europe), Barosaurus (similar to Diplodocus but with a longer neck), Mamenchisaurus (found in Asia and with an even longer neck than the former), and Saltasaurus (South-American, Cretaceous, and with an unusually armored body). Other sauropods have been relatively common as well either because of their historical relevance (ex. Titanosaurus), for their distinctiveness (ex. Shunosaurus, Amargasaurus), because they're the prototypes of their own sauropod family (ex. Dicraeosaurus, Vulcanodon), or for other reasons — ex. Hypselosaurus has been thought the owner of the possible "biggest eggs" known from non-bird dinosaurs.
- Titanosaur is a often-heard name in documentaries, books and sometimes in pop-media: what is it exactly a titanosaur? Well, it has actually two meanings. The more strict one indicates a precise genus of Late Cretaceous dinosaur, Titanosaurus, the first sauropod discovered in India (and Asia), in year 1877. But its actually is one of the most fragmentary sauropods, known only from few vertebrae and some other material, and was treated as one of the three most classic dinosaurian wastebins together with Megalosaurus and Iguanodon: to the point that Titanosauruses cropped up everywhere in the world - now they are regarded either dubious, or reclassified in new genera. The second meaning indicates the sauropod subgroup including the eponymous genus above: Titanosaurs. First appeared in the Late Jurassic with Australodocus (initially believed a diplodocid, hence its name "southern [diplo]docus") they became a very abundant and widespread dinosaur group in Cretaceous, expecially in the Southern Continents (where competition from the more evolved Ornithischians was lower), and in the Late Cretaceus they managed to replace all the other sauropods. Here we list only some noticeable titanosaurian examples. Not all titanosaurs were true titans: among colossi such as Argentinosaurus, Puertasaurus, Futalognkosaurus, Paralititan, Dreadnoughtus, or Antarctosaurus, there was also an animal like Magyarosaurus, a dwarf sauropod only 6 m long, which reduced its size to survive in small European islands. Once often put in the "Titanosaurus wastebin", even though its name means "lizard of Hungary" it was found in the near Romania. About Antarctosaurus, this has been one of the first dinosaurs found in South America (since the start of the XX century: hence its generic name Southern Lizard), but is very poorly-known. Some alleged antarctosaur remains have been described in Africa and even India other than South America (the Indian one is now called Jainosaurus); some of these are nearly as big as those of Argentinosaurus found several decades later, as well as the equally-fragmentary remains of another early-discovered South-American kind, Argyrosaurus note Most titanosaurs, however, were far from the two extremes. The armoured Saltasaurus and the almost unutterable Opisthocoelicaudia, for example, were 12 m long—- still half the size of an average apatosaur.
- "Titanosaurus", Antarctosaurus, Argentinosaurus, Argyrosaurus and so on are not the only fragmentary titanosaurian kinds: ironically, despite the high number of described species, titanosaur remains are almost always very scant. Just as an example, Opisthocoelicaudia from Late Cretaceous Mongolia is considered one of the most complete together with Saltasaurus; its body, limbs and tail are well-preserved but its head and neck are unknown. The skeleton of Opisthocoelicaudia do not shows any sign of preserved body armor, and its tail is strangely curved upwards. It was originally classified as a Camarasaurus relative, as well as the less-known Asiatosaurus from Eastern Asia (maybe the first sauropod found in China, hence its generic name). But other titanosaurians, as said above, do show armor; these one were the most evolved, from Late Cretaceous, usually small-sized for sauropod standards. To compensate, the most primitive ones were often enormous-sized to defend themselves against predators like the carcharodontosaurids. Among small armored Late Cretaceous titanosaurian, other than Saltasaurus we can mention Laplatasaurus "La Plata lizard". Its name is reference to the famous Argentinian river near which it was found: "Rio de la Plata" means river of the silver in Spanish. Like Antarctosaurus, it too has to some degree been treated as a "wastebasket" (some alleged "Laplatasaurus" were once described in Africa). Another exception to the scant fossils is Dreadnoughtus schrani, discovered in 2005 with a 45% complete skeleton. Given that few of the bones were duplicates from the left and right sides of the D. schrani, it's de facto 70% complete. As most titanosaurs (and most very large sauropods in general) have only had specimens less than 10% complete, this means that while Dreadnoughtus is (probably) not the largest titanosaur, it's the dinosaur with the greatest mass that we can be reasonably certain about, at around 38 metric tons - and the specimen in question is believed to be a juvenile, so a full-grown adult might have been much bigger.
- Most titanosaurian remains are from South America, expecially Argentina. Most South American dinosaurs have been discovered in Argentina, and not in Brazil as one might expect, given the largest area of the latter. A rather enigmatic Argentinian sauropod is Chubutisaurus; found in the 1980s together with the meat-eating Carnotaurus, it was initially believed a late-surviving brachiosaurid, and some think it may be an intermediate form between brachiosaurids & titanosaurs rather than a proper titanosaur. Other examples of Argentinian (confirmed or putative) titanosaurs include Aeolosaurus, Andesaurus ("Andean lizard") , Campylodoniscus, Epachthosaurus, Ligabuesaurus, Neuquensaurus (formerly included inSaltasaurus), Pellegrinisaurus, and the recently-discovered Patagotitan ("Titan of Patagonia") and Notocolossus ("Southern colossus"), two brand new additions for the already-long "biggest sauropod" title. However, titanosaurians have been found in most parts of the world. Both Hypselosaurus and Ampelosaurus come from France; the latters status as the most complete French sauropod has made it a sort of national celebrity since its find in the late 1990s. Hypselosaurus priscus (known since the early 1900) is far more fragmentary, but is famous in popular dino-books because is classically thought the source of some large fossil eggs found in the XIX century; they are reputed the biggest dinosaurian eggs ever found, and yet theyre only one foot long - not exactly like those man-sized objects seen in cartoons. note . Aepisaurus, also found in Cretaceous France like the above, is known only from a humerus, and it's uncertain if it was a titanosaur or not. Among titanosaurs which fell in the Titanosaurus-Wastebasket, one of the most astonishing is Isisaurus from India. With its thick neck, short tail and strongly sloping backbone, it was the most giraffe-like sauropod known to date, even more than the well-known brachiosaurids. Just as strange were its forelimbs, with extremely reduced "feet". The very fragmentary Aegyptosaurus has received its name from the country it was found, Egypt; it lived in Cretaceous Northern Africa near another famous egyptian guy, Spinosaurus aegyptiacus.note And what about North America? Did any titanosaur live here, along with T. rexes and Triceratops? Yes, it did, but was the only one known: Alamosaurus, possibly a isolated migrant originally from South America. Even though is known only from (again ) not-complete remains, its status of the only one who met Tyrannosaurus rex in Real Life! (and its token sauropod appearance as well, without any known armor) has made it the perfect Hand Wave for those artists/writers who have fun to portray Apatosaurus/Diplodocus and Tyrannosaurus living side-by-side. Considering the extreme rarity of this eventuality, this would make Alamosaurus, not Brontosaurus or Diplodocus, the real Great-Stock sauropod.... Just as an example, the sauropod skeleton seen next to the Tyrannosaurus one at the end of the first Jurassic Park film has been labeled "Alamosaurus", but is more probably an Apatosaurus. Alamosaurus was found only in southwestern North America, while T. rex and Triceratops lived mostly farther north. There was some overlap between the two ecosystems, but only in a narrow area of Utah and Wyoming: thus, a battle between a T. rex and an Alamosaurus must have been a rare event. Extremely recent discoveries suggest that Alamosaurus may have been one of the largest sauropods, with fragmentary remains suggesting at animals equal or greater in size than Argentinosaurus.
Short neck, long tail: Dicraeosaurus
- Diplodocus and Apatosaurus had many relatives. Not only some real or alleged biggest dinosaurs ever (Supersaurus, Amphicoelias, Barosaurus), but also many other smaller, usually more primitive animals: Dicraeosaurus is perhaps the traditionally most known. Found in the famous Tendaguru deposit, Dicraeosaurus was 13-20 m long but weighed only 6 tons, no more than an elephant. Its the smallest member of the classic Late Jurassic African Sauropod Trio. The other two have usually been called Barosaurus and Brachiosaurus, but the former is Tornieria, while the latter is Giraffatitan. One Dicraeosaurus skeleton is mounted next to the more famous Giraffatitan one, in the Berlin Museum. Other less-known sauropods from Tendaguru include Janenschia (named from the discoverer of the site, Werder Janensch) and Tendaguria.
Spiny longnecks: Amargasaurus
- With its short, Apatosaur-like neck and a long, Diplodocus-like tail, Dicraeosaurus could have had a double ridge on its back, but this is not sure. His South American Early Cretaceous relative, Amargasaurus, surely had this. One of the most bizarre-looking sauropods, found in 1990 in Argentina, Amargasaurus had pairs of neural spines which arose from its neck. Perhaps these spines substained a double-sail, or maybe were covered in keratin, making them true spikes for defense. Considering its quite small size for a sauropod (10 m long and weighing less than an elephant), the latter option seems the more likely. Interesting, an Amargasaurus-like "sail" was added in the Primeval TV series to a totally different dinosaur, Dracorex (see Pachycephalosaurs). Described as recently as 2019, its close relative Bajadasaurus had also neural double-spines on its neck but pointing forwards, not backwards like Amargasaurus.
- Still another dicraeosaurid, the recently-discovered Brachytrachelopan (also South American but Jurassic) was even weirder; with its extremely shortened neck, it didn't seem even a sauropod! Indeed South America has gifted some other odd sauropods in recent years: the possible titanosaurian Bonitasaura had uniquely a horny beak put behind the frontal teeth. While Agustinia was thought to have had long, raised bony plates like a stegosaur, but these now appear to be misinterpreted normal bones. And in North America, Dyslocosaurus was believed to have had five claws on each rear-foot, unlike the typical three-clawed feet of every other sauropod. Returning to Brachytrachelopan, it's worth noting that the shortness of its neck was obtained not by diminuishing the number of vertebrae, but extremely-shortening each of them — the exact contrary than the modern giraffe, that has the typical seven neck-vertebrae of every mammal but very elongated. Other diplodocoids were still more primitive than the above: Rebbachisaurus from Cretaceous Sahara maybe still hadnt a whip-like tail. This sauropod was found in several African countries, but its remains are sparse; some alleged Rebbachisauruses were described in South America, but now are classified in other genera within the Rebbachisaurids (ex. Limaysaurus). This family also contains Nigersaurus from Niger, whose well-preserved skull shows strange grinding teeth. It also had the most teeth of any known saurischian: at any one time, there could be over five hundred teeth in its mouth - among dinosaurs only the ornithischian hadrosaurs had even more teeth in their mouths. In 2018 it was discovered that the legendary Amphicoelias fragillimus, known only from a single immense vertebra and long believed to be a gigantic diplodocid, was actually a member of the rebbachisaurid group. Msybe the most basal rebbachisaurid is Histriasaurus from Croatia. Some sauropods are controversial if they were diplodocoids, or not: Haplocanthosaurus could be a more basal sauropod. Found as early as the 1900s, lived alongside the stock sauropod trio "Apato"-"Diplo"-Brachiosaurus in Late Jurassic North America, but is rarer and extremely less-portrayed. Also living along the latter were Dystrophaeus (described by Edward Cope) and the dicraeosaurid Suuwassea ("ancient thunder"). "Eobrontosaurus" ("dawn thunder lizard") was described by Bob Bakker in 1998 as a very Apatosaurus-like new diplodocid genus, but it was in the 2015 merged again in the officially resurrected "Brontosaurus". While Cetiosauriscus (Middle Jurassic Europe) despite its name meaning "similar to Cetiosaurus" was not a basal sauropod like the latter, but a true diplodocoid. Two alleged diplodocoids were found in Late Cretaceous Mongolia in the 1970s: Nemegtosaurus and Quaesitosaurus, both known from one single Diplodocus-like skull. Since Late Cretaceous sauropods were titanosaurs, the question was: were they late-surviving diplodocoids, or just Diplodocus-like titanosaurs? In 2000, the discovery in Madagascar of Rapetosaurus, a very complete Late Cretaceous titanosaur with a clearly Diplodocus-shaped head, reveals the second option being the more likely.
- While diplodocoids are abundant, brachiosaurids are much rarer. Most described species are fragmentary, and with their appearance unknown. We can mention, because of their historical relevance, Astrodon and Pelorosaurus. Astrodon ("starry tooth") is the first sauropod found in North America (even before the Bone Wars), but is known mainly from teeth; other incomplete remains found within the "wars" were once referred as "Pleurocoelus" ("hollow side"). Astrodon is traditionally considered a small sauropod about 10 m long, and lived in Early Cretaceous along Deinonychus and the much larger Sauroposeidon. Some analyses, however, suggest Astrodon is not a brachiosaurid, but is closer to titanosaurs. Curiously, the synonym "Pleurocoelus" used to be described as a much bigger brachiosaurid than Astrodon. On the other hand, the English Pelorosaurus was probably as big as Brachiosaurus, but like Astrodon (and most non-stock brachiosaurids), lived in Early Cretaceous as well, and is very scanty. Some have depicted Pelorosaurus with an armored back like that of the titanosaur Saltasaurus, but it's dubious if it really had it. Pelorosaurus was the second (1850) sauropod described after Cetiosaurus, and lived together with Iguanodon, Hypsilophodon, and Baryonyx. Since sauropods were virtually unknown at the time the pelorosaur's find strongly astonished its describer, to the point he gave it its name meaning monster lizard. Later, Pelorosaurus was treated as a Waste-Basket taxon for undetermined European sauropods: among these former pelorosaurs (all dubious) we can mention "Dinodocus" from Early Cretaceous (not a Diplodocus relative as it seems), and "Gigantosaurus" (not Giganotosaurus), which lived in Late Jurassic earlier than the real Pelorosaurus. From the same period of "Gigantosaurus" comes another little-known european brachiosaurid, Bothriospondylus: even though is known since the early 1900, it has not fallen in the "pelorosaur wastebin" — but to compensate, it has been treated as a small "wastebin" on its own, assigning to it some fragmentary sauropod remains from Madagascar, now known as Lapparentosaurus. Also known since the late 1800 but equally not-fallen in the pelorosaurian wastebin are Chondrosteosaurus ("cartilage-bone lizard") and Macrurosaurus ("big tailed lizard"), both from England; the latter was an Early-Cretaceous relative of titanosaurs known only from 40 tail vertebrae. In Portugal, a formerly-believed species of Brachiosaurus is now labeled Lusotitan ("Portuguese titan"). Once, "Dystylosaurus" was also considered a brachiosaurid, but today is classified within the diplodocid genus Supersaurus.
- Together, Brachiosaurids, Camarasaurids, Titanosaurians, and others make the Macronarians, one of the two great sauropod subgroups together with Diplodocoids. One example of macronarian which do not pertain to the aforementioned subgroups is Euhelopus zdanskyi. The first-found non-fragmentary sauropod in China (and one of the very first found Chinese dinosaurs, in the 1920s), it had long neck and short tail which made it looking lik a miniaturized Mamenchisaurus. Indeed, Euhelopus ("good foot for swamps", originally called "Helopus", "foot for swamps") was once believed related with the mamenchisaur; but now is considered a more evolved sauropod, closely related with titanosaurians. Euhelopus is the most "classic" among Asian Early Cretaceous sauropods (other less-known examples are Chiayusaurus and Mongolosaurus), even though some old sources wrongly claim it was Late Jurassic, thus possibly living near Mamenchisaurus. note Thanks to this, the euhelopus could have been the model for Prehistoric Parks titanosaurs seen in the early Cretaceous episode about "Dino-birds". Another sauropod, the short-named Erketu from Late Cretaceous Mongolia, despite its comparatively small size is believed to have had the longest neck respect-to-the body of any sauropod - the polar opposite of the diplodocoid Brachytrachelopan, which has the shortest neck for any known sauropod. "Cathetosaurus" from Late Jurassic USA was originally described by James Jensen (the Supersaurus discoverer) in the '80s as the most apt sauropod to rear up on its hindlegs, but has then revealed to be a simple species of the well-known Camarasaurus. South-African Algoasaurus, found by Robert Broom in early 1900, was also once believed a camarasaurid, but is known only from a leg-bone. Lourinhasaurus from Portugal, on the other hand, seems a true camarasaurid. "Nurosaurus", a yet-undescribed sauropod found in 1991 in Inner Mongolia (province of China), has revealed to be one of the biggest Asian sauropods with its 25-meters-long body, rivalling the famous Mamenchisaurus. Among the other hard-to-classify macronarians, there is also the curious case of Europasaurus. Found in Europe, it lived in the Late Jurassic islets in which is today Germany; in spite of being one of the smallest (6 m) sauropods ever, it should have appeared a true giant to its two neighbors Compsognathus and Archaeopteryx. Europasaurus is not the only case of insular dwarfism among sauropods however: another case is the already-mentioned titanosaur Magyarosaurus from Romania, which was about the same size.
Sauropod or Stegosaur?: Shunosaurus
- Not every sauropod is either Diplodocoid or Macronarian (Diplodocoid+Macronarian =Neosauropod, "new sauropod"). Many were more primitive than both: Cetiosaurus and Mamenchisaurus are two prominent examples. Another famous basal sauropod is Shunosaurus, lit. "lizard from Shu": Shu is one of the old names of the famous chinese province of Szechuan, where most Jurassic dinosaurs come from. Shunosaurus, more in detail, lived in Chinese Middle Jurassic, before the much bigger Mamenchisaurus. Rather small (10 m long), relatively short-necked and with a round head filled with crammed teeth, it had the typical traits of a primitive sauropod.... except for its tail. It was very specialized, ending with a bony-club on its tailtip like an ankylosaur, surrounded by four short spikes like a stegosaur — in other words, a sauropod with a Thagomizer! note . Furthermore, with its 20 or more skeletons known, Shunosaurus has been one of the most common sauropod in fossil record, rivalling Camarasaurus. Its tail-club, however, was different than that of an ankylosaur: it was simpler in structure, formed by one single elliptically-shaped piece of bone at the end of the caudal vertebrae, while the "thagomizer" was made of spikes much shorter than stegosaurians. Similar to Shunosaurus but not related, Spinophorosaurus (meaningfully "spike-bearing lizard") discovered in 2009 in Middle Jurassic Africa had also a similar armored tail, with a thagomizer but not a club. It was probably even more primitive than Shunosaurus, and like the latter, is one of the best scientifically-known early sauropods today. Interestingly, its first two skeletons were digitally replicated after being brought in Europe, making Spinophorosaurus the first sauropod to have its skeleton 3D-printed.
- Shunosaurus lived alongside members of a mostly Asian sauropod subgroup, the Mamenchisaurids, which included other kinds other than the namesake Mamenchisaurus, the best-known of them has been Omeisaurus. This one ("Omei lizard") lived in Late Jurassic like the mamenchisaur, an like the latter was described by the father-of-chinese-paleontology Yang Chung Chien in the 1940s. Smaller than Mamenchisaurus (20 m long) but with a very long slim neck and comparatively short tail, Omeisaurus looked like a smaller version of it, but is known to have had a tail-club very similar to that of Shunosaurus (but without the "thagomizer"). Several confirmed species are known from Omeisaurus (an unusual thing among dinosaurs as a whole) and yet this dinosaur has not been a common sight in books. Other mamenchisaurids were more generic-looking, for example the medium-sized Tienshanosaurus (also described by Young Chung Chien from good remains including even some egg fragments), while the equally middle-sized Datousaurus and the very small Bellusaurus were considered mamenchisaurids but probably weren't. All these animals were found in China, but one mamenchisaurid appears to be present in the African Tendaguru formation. Outside Asia, one of the most relevant primitive sauropod has been Patagosaurus from Patagonia and, more recently discovered, Jobaria from North Africa. Both were Middle Jurassic, even though the latter was believed Cretaceous, thus a late-surviving form. Patagosaurus is still the most well-known sauropod from Jurassic South America; known from eight adult individuals and one juvenile, was very similar to Cetiosaurus in shape and size. Indeed, most generic-looking basal sauropods used to be put in the "Cetiosaurid" family, but this was actually an artificial assemblage. Others South-American Jurassic sauropods include Amygdalodon ("almond-tooth") and Volkheimeria (named after a German scientist). But the most spectacular — yet still surprisingly obscure, even among many dino-fans — basal sauropod is surely the Spanish Turiasaurus described in 2006 from the boundary between Jurassic and Cretaceous (this was a late-survivor); 30 m long and massively-built, it's the biggest known basal sauropod, with a similar size of an Argentinosaurus and other colossal titanosaurians! It has recently become the prototype of its own lineage of basal sauropods, the Turiasaurians, which include other smaller sauropod found in Spain from the same period, namely Galveosarus and Losillasaurus. Aragosaurus ("Aragon lizard"), also from Spain, is of uncertain classification: it was originally considered a camarasaurid, but could be another turiasaurian as well.
- All the sauropods already listed in this page were "Eusauropods" ("real sauropods"). Yet, there were even more basal sauropods other than these: Vulcanodon and Barapasaurus are the two classical examples. Both from Early Jurassic, they still had prosauropod traits in their skeletons, but their external shape was already sauropodian, with pillar-like limbs and elephant-like feet. Discovered in the '70s in Rhodesia (today called Zimbabwe), Vulcanodon strange name means volcano tooth - this because was found in sandstone, but its actual teeth are unknown, since its skull hasn't been found yet. The teeth that have given the name to it actually belonged to an unclassified theropod who could have eaten its carcass in life. Vulcanodon lived alongside a small coelophysid named "Syntarsus" (today called Coelophysis rhodesiensis). Vulcanodon was very small for a sauropod — 6 m long, less than a plateosaur. On the other hand, Barapasaurus ("big-legged lizard", not to be confounded with Barosaurus above) was the first known sauropod to have reached the classic huge sauropodian size: 18 m long, like Camarasaurus or Cetiosaurus. Its also one of the few dinosaurs from India, while the vulcanodont was Southern African and lived alongside the well-known prosauropod Massospondylus. Other examples of vulcanodontids or putative vulcanodontids (all small-sized) include Ohmdenosaurus from Germany, Tazoudasaurus from Morocco, Kunmingosaurus and Zizhongosaurus from China, and Kotasaurus from India. Even more ancient than all these (hailing from Late Triassic) was Isanosaurus from Thailand, described as the most ancient known true sauropod when it was found. About Melanorosaurus and other sauropod ancestors, see in the following section.
- Sauropods have been found almost everywhere, Land Down Under as well (but still not in Antarctica, unlike "prosauropods"). But are little-known there. Austrosaurus and Rhoetosaurus are two rarities in books, less-frequent than smaller Australian dinosaurs like Leaellynasaura, Minmi, Muttaburrasaurus, or even the alleged dwarf allosaur; this can be justified though, giving their scarse remains. Rhoetosaurus (its name comes from a Greek giant) still remains one of the few known Australian dinosaurs from the Jurassic note (most known aussie dinos were Early Cretaceous): it is a basal sauropod maybe related with Cetiosaurus, or maybe even more primitive. On the other hand, Austrosaurus ("southern lizard") was a typical Early Cretaceous dinosaur; Late Cretaceous dinosaurs are still unknown from Australia. It is more incomplete but more peculiar than Rhoetosaurus, having unusually-long forelimbs; once, Austrosaurus was believed a primitive late-surviving non-diplodocoid / non-macronarian sauropod; today is classified as a titanosaurian. Very recent additions in the australian sauropod list are Diamantinasaurus and Wintonotitan, and others could join them in the future.
Titan or Atlas?: Atlantosaurus
- An almost-forgotten-today but very-important-once sauropod is "Atlantosaurus" (Atlas lizard) note ; the first sauropod discovered within American Bone-Wars, initially classified by Marsh as "Titanosaurus" — the word was just used few months before for the valid Titanosaurus! Both Atlas and the Titans were immense-sized Greek Mythology goddities: Atlas has traditionally been portrayed bearing the world on his arms. The name of the geographical "Atlas" comes just from this character. After its discovery, several undetermined sauropod material was attributed to "Atlantosaurus", making it a well-known kind of long-necked dinosaur: but later, scientists found that most of this material was actually based on Apatosaurus remains. Worsening things, the original "Atlantosaurus" is so incomplete to be regarded dubious genus today. However, to understand how much our atlantosaur was kept in consideration in the past, think this: it used to be often cited in old books and encyclopedias as the biggest creature ever appeared on Earth: one of the very first examples of dinosaur-related sensationalism. A tradition that still continues today: see an exhaustive list in the Stock Dinosaurs (True Dinosaurs) page.