Useful Notes / Prehistoric Life - Sauropods

Sauropods include about two hundreds of kinds described so far. Other than the stock ones, the five 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). Each one is listed in its own paragraph at the top of the page. 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.

A dino-sized injustice: Camarasaurus

Which is the most common sauropod in the USA, Apatosaurus, Brachiosaurus, or Diplodocus? None of them. It was Camarasaurus.

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

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

However, Camarasaurus was more related to Brachiosaurus than to Apatosaurus. Both the brachiosaur and the camarasaur had short, boxy skull with wide nasal openings, a nasal crest, and relatively large teeth which bordered the whole jaws - the Diplodocus and Apatosaurus skull was longer and flatter with peg-like teeth only on the jaw-tips. The four legs of Camarasaurus were about the same length, and its back was perfectly horizontal and perhaps even a bit taller on the shoulders: Apatosaurus and Diplodocus has shorter forelimbs than hindlimbs, and their back had a convex silhouette with the tallest point on the hips.

The longest neck: Mamenchisaurus

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

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

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

To date, the only significative apparition Mamenchisaurus has made in pop-culture was a simple cameo in The Lost World: Jurassic Park. It was unidentified and unnamed, maybe the only dinosaur in the Jurassic Park film-series that has not become Stock after that. As it seems, four pop-cultural sauropods are just too many.

Hearts everywhere: Barosaurus

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

Discovered in USA at the end of the Bone Wars, Barosaurus was the closest relative of Diplodocus, and lived as well in Late Jurassic North America; some possible remains from Africa are also known, but are generally thought to be from a different genus, Tornieria. Barosaurus was virtually identical to Diplodocus except for its shorter tail counterbalanced by the longer neck. Its was one of the longest sauropods, only a bit shorter than Diplodocus. Barosaurus means “heavy lizard”: though apt for a sauropod, it's not totally appropriate. Having the same slender frame of Diplodocus, the barosaur weighed less than other sauropods. At least, that was what we though up until 2016, when it was discovered that the fossils traditionally considered to belong to Supersaurus actually belonged to a gigantic member of this species, which would have been 150 feet long and weighed perhaps 100 tons!.

Its lower notoriety is probably due to the fact Barosaurus remains are less abundant than the Diplodocus ones. However, Barosaurus has gained more fame when a barosaur skeleton was mounted in the American Museum of Natural History in the 1980s. This skeleton is the dino-star of the museum, being mounted erected on the hindlimbs and the tail; 15 m tall, is shown defending its youngster from an attacking Allosaurus.

In the same years, one bizarre suggestion was made about its physiology: with such a long neck, Barosaurus may have had eight hearts to pump blood up to its lofty head. These "hearts" were imagined to be placed in four pairs through the neck, and pulsating synchronically to enhance the blood circulation. There could actually be a bit of reality in this idea: the problem is, there isn’t any evidence to prove all this true.

The armored brontosaur: Saltasaurus

When we think about “armored” dinosaurs, our mind automatically goes to things such as Stegosaurus, Triceratops, Ankylosaurus. Thus, if you are a layman, you could be astonished if we tell you that there was also an armored sauropod.

Scientists themselves were surprised when such an animal was discovered in 1980 in the Argentinian province of Salta: they called it Saltasaurus (not “Saltosaurus”, please). It walked around 80 million years after the more popular "three stock sauropod band", almost managing to see the meteor.

Saltasaurus armor was different-looking than Ankylosaurus armor. It had no spikes, and was made by several small bony scutes of different size, covering all the upper parts of its torso like a mosaic. note  Though apparently much lighter than an ankylosaur’s, it would have been enough to defend the sauropod against predators like the contemporary “horned” Carnotaurus. The scientific importance of Saltasaurus raised up even more after the discovery (made at the end of the 1990s) of a fossilized breeding-site full of nests and hatchlings, the very first known from a sauropod. These remains were attributed to Saltasaurus, but we are not sure if they pertain to its genus.

Saltasaurus is also a member of that subgroup of sauropods called titanosaurs (see below): since its discovery, armor plates of several other titanosaurs have since been found, although more incomplete. However, Saltasaurus was considerably smaller than many other sauropods (it was only 12 m long and not much heavier than an elephant); and, not counting the bony plates, its shape was that of a generic sauropod. This might partially explain why, despite its badass-look, Saltasaurus has remained a non-fictional animal unlike Carnotaurus.

A whale of dinosaur: Cetiosaurus

Which were the biggest animals ever, whales or dinosaurs? Hard question, depends on what criterium you want to use. Cetiosaurus, the first sauropod ever described, just means “whale-lizard”. But this is not a mere reference to its huge size; it was literally believed a whale-thing at one point.

First found in 1842 in England slightly after Richard Owen coined the word “dinosaur”, its first remains were so incomplete that Owen couldn’t believe such a heavy animal could live on land. Since limb bones were missing, he thought the owner was a non-dinosaurian marine reptile (remember sea-reptiles were already very well-known at the time). When the limb bones were discovered several decades after, the familiar image of an elephantine “reptile” with long neck and tail came to light.

Though not a Wastebin-taxon like Megalosaurus, Cetiosaurus could thus be seen as its sauropodian equivalent - incidentally, lived just alongside Megalosaurus in Middle Jurassic Europe, but has been found in North Africa too. Cetiosaurus has been the archetypical “basal” sauropod, and lived before the Stock Trio. Among the cetiosaur's primitive traits, it had compact vertebrae instead of hollow - cavities in the backbone is a typical feature of more evolved sauropods like Apatosaurus, Diplodocus, Brachiosaurus and Camarasaurus (the latter’s name just meaning lizard with cavities).

Unfortunately for Cetiosaurus, these sauropods were discovered in North America just in the period of the former’s correct interpretation, Their bigger size and/or their greater completeness meant Cetiosaurus was progressively put under the table. Making things worse, the cetiosaur has also a very generic look with no external traits that would make it recognizable. In short, this “whale of dinosaur” was predestined to become an only-book animal - expecially British books, as it could be qualified the "national" UK sauropod.

Titanic lizards: Titanosaurus, Antarctosaurus & Opisthocoelicaudia

“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. Ironically, it’s actually is one of the most fragmentary sauropods, known only from few vertebrae and some other material, but 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 (Australodocus), 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, 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. 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 (see Stock Dinosaurs), 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 apatosaur.

"Titanosaurus", Antarctosaurus, Argentinosaurus, Argyrosaurus and so on are not the only fragmentary kinds however: 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 (Opisthocoelicaudia was originally classified as a Camarasaurus relative), and its tail is strangely curved upwards. But other titanosaurians 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" note ; like Antarctosaurus, it too has to some degree been treated as a "wastebasket" (some alleged "Laplatasaurus" were once described in Africa).

An exception to the scant fossils is the 2005 of Dreadnoughtus schrani], discovered in 2005 with a 45% complete skeleton. And given that few of the bones were duplicates from the left and right sides of the D. schrani, it's de facto 70% complete. Most titanosaurs (and most very large sauropods in general) have only had specimens less than 10% complete. This means that while 'D. schrani 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.

Titanic lizards 2: Alamosaurus, Hypselosaurus & Isisaurus

Most titanosaurian remains are from South America, expecially Argentina. Actually, 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.

However, titanosaurians have been found in most parts of the world. Both Hypselosaurus and Ampelosaurus come from France; the latter’s status as “the most complete French sauropod” has made it a sort of national celebrity. Hypselosaurus is far more fragmentary, but is famous 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 they’re only one foot long - not exactly like those man-sized objects seen in cartoons. note .

Among titanosaurs which fell in the Titanosaurus-Wastebasket, 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. Other African countries which have left important dinosaur remains are: Tanzania (with the famous Tendaguru site full of Late Jurassic specimens note ); South Africa (home for several Early Jurassic dinosaurs note ), and several saharian countries other than Egypt, expecially Niger (home for Ouranosaurus and other Cretaceous animals).

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) has made it the perfect Hand Wave for those artists/writers who have fun to portray Apatosaurus and Tyrannosaurus living side-by-side. Considering the extreme rarity of this eventuality, this would make Alamosaurus, not “Brontosaurus”, 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 by some sources "Alamosaurus", but is clearly an Apatosaurus. More 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.

Diplodocus' kin: Dicraeosaurus, Amargasaurus & Rebbachisaurus

Diplodocus (and Apatosaurus of course) had many relatives. Not only some real or alleged “biggest dinosaurs ever” (Supersaurus, Amphicoelias), but also many other smaller, usually more primitive animals: Dicraeosaurus for example. Found in the famous Tendaguru deposit, Dicraeosaurus was 13-20 m long but weighed only 6 tons, no more than an elephant. It’s 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. Other less-known sauropods from Tendaguru include Janenschia and Tendaguria.

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 (weighing less than an elephant), the latter option seems the more likely. Interesting, an Amargasaurus-like "sail" was added in the Series/Primeval TV series to a totally different dinosaur, Dracorex (see Pachycephalosaurs).

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.

Other diplodocoids were still more primitive than the above: Rebbachisaurus from Cretaceous Sahara maybe still hadn’t 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. 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.

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 Eobrontosaurus (a very Apatosaurus-like diplodocid found in the late 1990s, which has partially resuscitated “Brontosaurus” in the official dinosaur list), and the primitive Suuwassea. While Cetiosauriscus (Middle Jurassic Europe) despite its name meaning "similar to Cetiosaurus" was not a basal sauropod like the latter, but a true diplodocoid.

Finally, two examples from Late Cretaceous Mongolia: Nemegtosaurus and Quaesitosaurus, both known from one single Diplodocus-like skull. Since Late Cretaceous sauropods were titanosaurs, the question is: 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.

Brachiosaur’s kin: Astrodon, Pelorosaurus & Euhelopus

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. The former ("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". Astrodon is considered a “small” sauropod about 10 m long, which 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. However, it was the second (1850) sauropod described after Cetiosaurus, and lived together with Iguanodon and Hypsilophodon. 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: one of these former “pelorosaurs” is the dubious but coolly-named "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. Also known since the early 1900 but equally not-fallen in the wastebin is Macrurosaurus, an English Early-Cretaceous titanosaurian known only from 40 tail vertebrae.

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. The first-found 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 (its contemporaneous relative Erketu would have looked the same). Euhelopus was once believed related with the mamenchisaur; but now is considered a more evolved sauropod, closely related with titanosaurians. Being the most classic among Asian Early Cretaceous sauropods, Euhelopus could have been the model for Prehistoric Park’s “titanosaurs” seen in the early Cretaceous episode about "Dino-birds". Another interesting macronarian is Europasaurus from Europe; living in the Late Jurassic islets in which is today Germany, it was one of the smallest (6 m) sauropods ever, but should have appeared a true giant to its two neighbors Compsognathus and Archaeopteryx.

Nobody's kin: Shunosaurus, Omeisaurus & Patagosaurus

Not every sauropod is either Diplodocoid or Macronarian (Diplodocoid+Macronarian =Neosauropod, "new sauropod"). Many were more primitive than both. Cetiosaurus and Mamenchisaurus have already been mentioned: another relevant basal sauropod is Shunosaurus, from Chinese Middle Jurassic. Rather small (10 m long) and short-necked, it’s worthy of note for two things: its bony-club on its tailtip surrounded by four short spikes, resembling a combination between a Stegosaurian and Ankylosaurian tail note ; and the fact that, with its 20 or more skeletons known, Shunosaurus is one of the most common sauropod in fossil record, rivalling Camarasaurus. Similar but not related, Spinophorosaurus ("spike-bearing lizard") discovered in 2009 in Jurassic Africa had also a similar armored tail.

The shunosaur lived alongside members of a mostly Asian sauropod subgroup (the mamenchisaurids) which included also Mamenchisaurus and Omeisaurus. The latter lived in Late Jurassic like the mamenchisaur, was smaller (20 m long) but with a very long neck as well, and is also known to have had a tail-club (but without "spikes"). Several species are known from Omeisaurus, and yet is not a common sight in books. Other mamenchisaurids were more generic-looking, for example the medium-sized Datousaurus and the smaller Bellusaurus. Interestingly, a mamenchisaurid appears to be present in the African Tendaguru formation.

Outside Asia, primitive sauropods include Patagosaurus from Patagonia and Jobaria from Africa – both Middle Jurassic, even though the latter was believed Cretaceous, thus a late-surviving form. Patagosaurus is 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. Also interesting is the Spanish Turiasaurus from the boundary between Jurassic and Cretaceous (this was a late-survivor); 30 m long, it's perhaps the biggest known basal sauropod (not much smaller than Argentinosaurus!)

The first steps: Vulcanodon & Barapasaurus

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 two main examples. Both from Early Jurassic, they still had “prosauropod” traits in their skeletons, but their external shape was already sauropodian, with pillar-like limbs.

While Vulcanodon (whose strange name means “volcano tooth”) was very small for a sauropod (6 m long, less than a plateosaur), Barapasaurus (not to be confounded with Barosaurus) was the first known sauropod to have reached the classic huge sauropodian size (18 m long). It’s also one of the few dinosaurs from India, while the vulcanodont was Southern African and lived alongside the well-known prosauropod Massospondylus. About Melanorosaurus and other sauropod ancestors, see in the following section.

Long-necked Aussies: Austrosaurus & Rhoetosaurus

Sauropods have been found everywhere, Land Down Under as well. But are little-known there. Austrosaurus and Rhoetosaurus are two rarities in books, less-frequent than smaller Australian dinosaurs like Leaellynasaura or even the alleged “dwarf allosaur”; this can be justified though, giving their scarse remains. Rhoetosaurus still remains one of the few known Australian dinosaurs from the Jurassic (most known aussie dinos were Early Cretaceous): it is a basal sauropod maybe related with Cetiosaurus. On the other hand, Austrosaurus was Early Cretaceous; it had unusually-long forelimbs, and was once believed a primitive 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”); 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! note . However, most "Atlantosaurus" material was based on Apatosaurus remains, while the original "Atlantosaurus" is so incomplete to be regarded dubious genus. To understand how much our atlantosaur was kept in consideration in the past, think this: it used to ben often cited in old books 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 page.