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Argentinosaurus huinculensis Mk. II

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By Paleo-King   |   
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© 2017 - 2020 Paleo-King
Location: Plaza Huincul, Argentina
Time: Cenomanian epoch (beginning of the Late Cretaceous)
Length: 37m (122ft.)
Probable mass: 90+ tons

Finally, an Argentinosaurus that's reasonably true to life! While the original paleo-king.deviantart.com/art/… was cutting-edge for its time, and inspired many tributes, it was long overdue for an update.  Argentinosaurus is completely redone with the next-gen Paleo King treatment! Based on new material of closely related titanosaurs Patagotitan and Rukwatitan, and with the more distant Malawisaurus as the third gap-filler, this hi-fi skeletal completely rewrites the shape of Argentinosaurus. And with the revised proportions, the case is once again looking very good that this is still the biggest known dinosaur, at a whopping 37m. I am not going to do a life profile in case yet more complete relatives are found which force further revisions of the skeletal, which is far more easily updated. But this revision is probably the most radical relative to the old version, and makes all previous Argentinosaurus restorations - both mine and those of others, not to mention anything from Horizon and the BBC - obsolete.

The proportions of Puertasaurus shall also have to be updated based on recent lognkosaur discoveries (i.e. Patagotitan, Dreadnoughtus) so we can see how the two stack up: fav.me/d3lfqci). And then there's the Mexican Alamosaurus, as well as Patagotitan, which may still exceed it in mass. So far though, Argentinosaurus may at least top them in length.

As in all of the best rigorous skeletals, this one is a hybrid, with the most relevant species consulted first. Scaling up the hips and lower cervicals of Rukwatitan, we end up with a neck considerably longer than in previous Argentinosaurus reconstructions - and Rukwatitan does appear to be the closest relative of Argentinosaurus yet found, based on cladistics. The limbs are based on the type and referred material, along with Patagotitan and Rukwatitan for the shoulder, humerus and ulna, and Andesaurus and Dreadnoughtus for the manus and pes. The skull is modeled on the mysterious and never formally described skull (likely heavily restored) sometimes associated with Argentinosaurus on the web: 1.bp.blogspot.com/_u6CUqDWU5nw… The shape of this skull looks somewhere in between the skulls of Euhelopus and Malawisaurus, which cladistically also makes sense. The neck and tail are composites of Rukwatitan, Patagotitan and Malawisaurus, with some input from Ruyangosaurus on the problematic and heavily eroded final dorsal.

Argentinosaurus is a basal titanosaurian sauropod (sometimes classed in the dubious family Andesauridae, though it may form its own clade "Argentinosauridae" along with Rukwatitan), and probably reached a length of 122 ft (37m) - considerably larger than previous estimate which did not take the proportions of its smaller cousin Rukwatitan into account. It's known from two specimens - one consisting of some enormous dorsal and hip material plus a fibula (NOT a tibia as Bonaparte and Coria originally claimed in 1993), and the other being a femur shaft that is missing both ends. Its neck and tail are totally unknown, but based on related basal titanosaurs, it's likely that both were long, with the neck rivaling some euhelopodids in proportions, if Rukwatitan is any clue to its design. A more complete femur roughly 2.5m long was referred to Argentinosaurus by Bonaparte in 1996, though whether it's from the holotype individual or an altogether new specimen is unknown (and the book Bonaparte published it in is now long out of print and obscenely expensive).

Argentinosaurus had a long torso. Here I have restored it with 11 dorsal vertebrae (the standard count for most macronarians, including basal titanosaurs and most basal somphospondyli). The described dosrals are largely exposed without right-side ribs, so you can see their true shape. Salgado and Powell (2010) revised the order of the dorsals in comparison with other titanosaurs, reassigning the "first" dorsal described in 1993 by Bonaparte and Coria to the position of third dorsal, moving the supposed "third" dorsal to fourth dorsal position, and sorting out the placement of the posterior dorsals. I used this new ordering here. The final dorsal, heavily eroded and never figured in print, appears to be in the eleventh dorsal spot, the "dorso-sacral" which transitions to a sacral vertebra in lognkosaurs and other intermediate groups, reducing the dorsal count to 10 (and is caught midway through the act of this evolution in the colossal Ruyangosaurus).

References:

- Bonaparte, J.; Coria, R. (1993). A new and gigantic titanosaurian sauropod from the Rio Limay Formation (Albian-Cenomanian) of Neuquen Province, Argentina. Ameghiniana 30 (3): 271–282

- Bonaparte, J.F. (1996b). Dinosaurios de America del Sur. Museo Argentino de Ciencias Naturales, Buenos Aires.

- Carpenter, Kenneth (2006). Biggest of the Big: A Critical Re-Evaluation of the Mega-Sauropod Amphicoelias fragillimus, Cope, 1878. In Foster, John R.; Lucas, Spencer G.. and Geology of the Upper Jurassic Morrison Formation. 36. New Mexico Museum of Natural History and Science Bulletin. pp. 131–138.

- Mazzetta, Gerardo V.; Christiansen, Per; Fariña, Richard A. (2004). Giants and Bizarres: Body Size of Some Southern South American Cretaceous Dinosaurs (PDF). Historical Biology 65: 1–13. www.miketaylor.org.uk/tmp/pape…

- Salgado, L.; Powell, J. E., 2010. Reassessment of the vertebral laminae in some South American titanosaurian sauropods Journal of Vertebrate Paleontology Vol. 30 , Iss. 6,2010
Image size
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Comments81
anonymous's avatar
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Crystalgi's avatar

It's sooooo big! Yikes!

Dgrano20's avatar

I'm currently building a model based off your reconstruction hear. I've run into an issue with my model as I dont know the proportions of its rib cage as a head on view like your earlier models. Will you eventually be doing a full break down of the animal as you've done before? Also have you done any digital 3D models?

Thalassophoneus's avatar
It's a truly beautiful skeletal and it looks far more believable than all the diplodocid and saltasaurid versions circulating the internet.

I'm still kinda cautious with using Rukwatitan. I noticed that bricksmashtv's newest version of the sauropod phylogenetic tree shows it to be a close relative of Rapetosaurus rather than a basal titanosaur. What do you think about that?
DinoGuru's avatar
What's your thoughts on Gunnar's estimate of the 299cm Argentinosaurus femur?  
Cadrophemus's avatar
Great stuff, even better than the old one. BTW, what's with the 73 ton estimate by Mazzeta?
KaprosuchusDragon's avatar
KaprosuchusDragonHobbyist Digital Artist
will you do a puertasaurus skeletal?
zeSmollestBirb's avatar
We're gonna need a bigger tank.
Strick67's avatar
Big chap.
SameerPrehistorica's avatar
SameerPrehistoricaProfessional Digital Artist
Very nice skeletal. Previously when some people reduced it's weight at 70 - 80 tonnes, i always put it upto 90 tonnes. No matter how many giant sauropods are known, still Argentinosaurus is holding the popularity very well. Seems like i have to put the old estimate again which they mentioned for the first time - 80 - 100 tonnes. 
Majestic-Colossus's avatar
By the way, I saw an old discussion between you and Zach Armstrong about neck posture, from 2011. Looking at this colossal neck and others such as Sauroposeidon, Brachiosaurus, Mamenchisaurus' necks, I just can't see how a horizontal or semi-horizontal posture would even fit the animal's needs... 

A 10m+ long neck would be incredibly hard to maneuver among trees, the animal would probably miss a lot of food that it would barely even see with that posture. If the goal is to feed on low vegetation, but remaining big enough to scare predators away (or any other purpose to be a giant), why not develop "short" necks like that of Saltasaurus? A 7m neck would already be enough for an Argentinosaurus-sized sauropod to be a low grazer or eat at the height of its shoulders, being also easier to maneuver. We know the Mesozoic had plenty of trees tall enough for these sauropods to take advantage of, so why wouldn't they? Why would they compete with smaller species for low to mid vegetation? Sounds like an enormous waste of resources to maintain a horizontal posture when you have a 10-15m long neck. Such neck just doesn't make sense in a horizontal posture.

That's of course, assuming the neck was mostly for feeding purposes.
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
Yes, that's just what I've been saying. If you're going to low-graze, a shorter neck makes more sense. That's why apatosaurs and dicraeosaurs had shorter ones. Also a shorter neck is much easier to hold horizontal because gravity acts on the entire span of a horizontal neck, but only a small fraction of the length of a vertical one. The "gravity shadow" effect. Basic Pythagorean physics, really. It's one of those things, like sauropods not needing long tails to balance their necks, that pop-science and mainstream documentaries mislead people on, OVER and OVER again.

The only reason for very long necks is if you're going to do some high-browsing at least part of the time. And holding them vertical is the easiest posture, less strain on the neck tendons and cartilage.

I don't know why Zach has consistently favored horizontal necks in macronarians. It's maladaptive to have the neck that way in real life. Maybe he does it for measuring purposes. But I do know that the "ONP" phenomenon has become almost a dogma to a lot of people even though it's not supported by live animals. No living animal holds its neck out front stiff as a board. Even short-necked diplodocids still have a bit of curve to the neck. Kent Stevens, we can at least say, is taking ONP to an ideological level where he seems not to care if it dislocated the zygapophyses or snapping the spinal cord. He flat-out mocks other scientists with phallic adjectives and his fictitious "coffee conversations" between long-dead paleontologists. But Zach? Your guess is as good as mine.
Majestic-Colossus's avatar
By the way, I forgot that Supersaurus existed... And it most likely had a "horizontal" posture, even though it had a huge neck.
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
The neck posture and shoulder height in Supersaurus is however debatable... We have some people like Gunnar here who think maybe Scott Hartman was incorrect to assess the ulna as being from a different species. I scaled it down, assuming it's from an even bigger individual than the specimens known... but Gunnar suspects it could indeed belong to an animal in the same size range as the BYU material. If that's true, we could have a Supersaurus with higher shoulders, a bit more like Apatosaurus ajax... and potentially a steeper neck incline with the base already being tilted up higher.

Then the very long neck would make more sense. But we still don't have a skull, so the mouth shape is a mystery. If it were rounded like Tornieria, then high-browsing is a strong possibility. If it's square, a vaccum-mouth, despite that huge neck, then we're all really, really confused :D
kirkseven's avatar
Nice work here.
yty2000's avatar
So Argentinosaurus and Rukwatitan are sister taxons due the similarities in the pelvis?
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
Well the closest thing to "sister taxons" that we can get so far. Rukwatitan, by both the strict parsimony and Bayesian methods, comes out intermediate  between Andesaurus and Malawisaurus in the description's cladistic analysis - which is exactly where Argentinosaurus would be, even though it wasn't used in the paper's analysis. So both the pelvis shape and the characters in the study put it very close to the node/branch position of Argentinosaurus. And critically, it's the closest relative of Argentinosaurus that we can actually cross-scale the neck from. Even though Malawisaurus is more complete, it's not as closely related (it's already gotten rid of hyposphenes entirely, and has a very different neural arch structure). And Patagotitan isn't known from any ilium or sacrum material.
yty2000's avatar
There's a bunch of sauropods that fell into the "more derived than Andesaurus, but not as derived as Malawisaurs" category, hopefully we will get enough data in the future to sort out the relationship between these dinosaurs.
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
True, this is a murky place in the titanosaur family tree. Where exactly is the fork between Malawisaurus and true lognkosaurs, and where Patagotitan and Ruyangosaurus fit relative to that split, is a mystery. Savannasaurus at least looks enough like Malawisaurus to give it its own valid family. Argentinosaurus and Rukwatitan are probably more basal than the fork point, but where they fit between Andesaurus and that fork is unknown.
SpinoInWonderland's avatar
Aside from Rukwatitan, Malawisaurus would be the next best thing to use, I'm assuming? Correct me if I'm wrong.
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
Malawisaurus is not bad, given how little else there is in terms of close relatives. After Rukwatitan and Patagotitan, it's the next best filler for the gaps. The problem with it is the proportions of Malawisaurus, not necessarily the shapes of the individual bones - it's got much shorter neck proportions and also it composite of several specimens, so the hip-neck proportions are tough to gauge accurately. With Rukwatitan, there's just one specimen that has both. I used Rukwatitan to cement the proportions as close to Argentinosaurus would have been. Then I filled in most of the rest with Malawisaurus material, but scaled to fit the enlarged Rukwatitan-based hips-neck proportions of the template. The neck of Malawisauus would not have been this long, but the shapes of most of the vertebrae are closely based on it. There's a bit of Patagotitan there too, the the dorso-sacral is partially based on Ruyangosaurus (2014).

But yes, much of this skeletal uses Malawisaurus (mainly neck and tail material), scaled to Rukwatitan proportions. Just not the hips, limbs, shoulder, or head! Those are Rukwatitan, Patagotitan, the mysterious skull photo, and a fair bit of speculation. Good thing Rukwatitan includes humeri, so we don't have to use Andesaurus there. I'm not sure how accurate Bonaparte's reconstructed Andesaurus humerus is, even if it did base the plaster top end on a "natural cast" in the stone matrix.
christina1969's avatar
Well, I guess I'll wait until Gunnar updates his Argentinosaurus, as it seems to me that Scott, Franoys and Randomdinos goes by the "make it as small as possible" rule, you go by the "make it as big as possible" rule, and Gunnar is in the middle.
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
I actually don't go by the "make it as big as possible" rule. What I "wanted" Argentinosaurus to look like was the old version, which was 33m. That's before we had Rukwatitan and Patagotitan. Now with Rukwatitan having both the ilium, anterior caudals, and the lower cervicals, it's possible to cross-scale the neck and tail with Argentinosaurus. I didn't expect Argentinosaurus to be this big, but that's how it would be if its proportions were anything like its closest relative. I actually reduced the tail proportions on this one relative to how they would have scaled up from Rukwatitan, because of how small the last few preserved sacral centra are. (If it was a straight Rukwatitan clone, it would have longer limbs and be over 40m long).

BTW, my Puertasaurus and Ruyangosaurus will probably have to be downsized. More new evidence from related animals reduces them, but new evidence increases Argentinosaurus!
christina1969's avatar
Answer please :(
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
It's actually metric tons.

You're funny.
anonymous's avatar
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