Paleo-King's avatar

Paluxysaurus jonesi hi-fi skeletals

81 25 4K (4 Today)
By Paleo-King   |   
Published:
© 2017 - 2020 Paleo-King
The two main individuals known from Paluxysaurus jonesi (there are several others which have not been photographed/published). This was a tough skeletal due to the lack of photo references for much of the catalogued material, and due to the FWMSH material being split up piecemeal into many specimen numbers irrespective of which individual skeleton the bones came from. The holotype is just the nasal and maxilla, though most of the material figured here for the FWMSH specimens is likely from the same individual. The TMM museum, for their part, at least used the same specimen number for all the bones from its lone individual skeleton. More museums should do that, it makes things SO much easier.

Paluxysaurus jonesi

Family: Chubutisauridae (basal Somphospondyli)
Time: Early Cretaceous, Albian epoch, ~110 mya
Location: Twin Mountains formation, Trinity group, Jones Ranch, Texas, USA

The larger individual (TMM 42488) probably massed around 17 tons and appears to be mature or close to it. Adult Paluxysaurus were therefore too big for Deinonychus and even Utahraptor to tackle (unless it was a pack of them), but still within range of Acrocanthosaurus' menu.

This is the best-known of the Early Cretaceous titanosauriforms from Texas. It was closely related to the much larger Sauroposeidon, but contra D'Emic and Foreman (2012) appears to be a different genus due to variations in the laminae, the size and spacing of various processes in the dorsals, and the TMM specimen having a mostly fused coracoid (and thus indicating Paluxysaurus reached maturity at a much smaller size).

What is more certain from D'Emic and Foreman's research, for both animals, is that they are clearly more derived than the brachiosauridae, and their unique twisted interlock of the radius and ulna, widely spaced prezygapophyses, small centrum and higher neural arches, distal taper to the femur, and other unique traits put them firmly in a clade with Chubutisaurus and its odd tall-spined cousin Ligabuesaurus, and the similarity of the Paluxysaurus skull material to Sarmientosaurus indicates it was also a chubutisaurid. "Angloposeidon" as well as the excellent Wealden pelvic material figured in Blows (1995) are likely also chubutisaurs, and the colossal French Monster is a strong candidate for this family as well: paleoking.blogspot.com/2014/07… , having a nearly identical in situ femur shape to Paluxysaurus, which shows no signs of gaps or displacement of fragments. The Chubutisauridae appear to be a couple of nodes more derived than brachiosaurs, with the "Laurasiformes" such as Tastavinsaurus, Venenosaurus, and possibly Astrophocaudia forming an intermediate clade between the two groups.

From the outside they still looked superficially like brachiosaurs, though with a more compact nose and a more gradual taper to the tail, and going by the Paluxy river footprints (likely made by Sauroposeidon), they also had a 4th toe claw on the foot, a feature not found in either brachiosaurs or titanosaurs (though a trackway in China's Gansu province indicates it may also be present in Huanghetitan). The odd dip in the tail is natural (in fact, I have relaxed it somewhat here). The kink in the femur is also a natural feature, one that is not found in some other chubutisaurs, but oddly enough was re-evolved in more derived somphospondyls like Euhelopus, Daxiatitan and Janenschia. At some point I plan to do a skeletal of the juvenile Sauroposeidon material from the Cloverly formation in Montana, and see how it comes out (even as a juvenile, Sauroposeidon had a more robust femur and more pronounced laminae than Paluxysaurus, and there are proportional differences in the dorsals and caudals too).


REFERENCES:

Rose, Peter J. (2007). "A new titanosauriform sauropod (Dinosauria: Saurischia) from the Early Cretaceous of central Texas and its phylogenetic relationships" (web pages). Palaeontologia Electronica. 10 (2).

D'Emic, M.D.; Foreman, B.Z. (2012). "The beginning of the sauropod dinosaur hiatus in North America: insights from the Lower Cretaceous Cloverly Formation of Wyoming". Journal of Vertebrate Paleontology. 32 (4): 883–902.
Image size
7104x6712px 4.38 MB
Comments25
anonymous's avatar
Join the community to add your comment. Already a deviant? Log In
KaprosuchusDragon's avatar
KaprosuchusDragonHobbyist Digital Artist
will you make a new version of sauroposeidon?
Majestic-Colossus's avatar
Can Paluxysaurus be used as a guide to draw the French monster?
Philoceratops's avatar
PhiloceratopsHobbyist General Artist
No, because that thing is a turiasaur.
Majestic-Colossus's avatar
Really? Any links? It would still be a massive dinosaur, something like 30% larger than Turiasaurus (linearly) and probably around twice the body mass.
Philoceratops's avatar
PhiloceratopsHobbyist General Artist
:iconbricksmashtv: might be able to help....
rhe416's avatar
rhe416Hobbyist Traditional Artist
Isn't Paluxysaurus a junior synonym of Sauroposiden?  
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
No, because they are separate genera. I don't support lumping them together. There is a juvenile Sauroposeidon specimen which shows some differences in the vertebrae and limbs with Paluxysaurus (it is more robust, even as a juvenile), and the larger of the two main Paluxysaurus skeletons appears to be close to adult size, with the shoulder suture beginning its fusion. It's much smaller than the big Sauroposeidon type specimen.
rhe416's avatar
rhe416Hobbyist Traditional Artist
I wasn't at all aware of this. Thanks :)  
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
Well the habit of lumping the two into one genus and species is mainly from D'emic and Foreman's paper. It's their theory, not something universally accepted by paleontologists.

Plenty of people are skeptical of the theory. But the idea that they're both somphospondyls (and closely related ones) rather than brachiosaurs, is far more likely to be true. I can get behind that, given how these two animals have very similar dorsals and forearms to Chubutisaurus.
Gamerey's avatar
What do you think of the Price River Quarry 2 Somphospondyl?  Was it Paluxysaurus or Sauroposeidon, a close relative, or something entirely different?
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
The Price River material is still a mess, so until that area is better studied it's hard to say.

What I do know is that both Paluxysaurus and Sauroposeidon have a rather distinct shape to the Humerus, and in these formations you get some humeri that look like them, but also others that look more like Brachiosaurus or Sonorasaurus. Depending on how the stratigraphy pans out, we could be looking at the evolution of North American brachiosaur and chubutisaurs across several genera and strata.

Perhaps some of it will look like Tendaguru, where Giraffatitan appears to have 2 or 3 species in the different "saurian marl" layers, as do Dicraeosaurus and Tornieria.
Gamerey's avatar
The fact that these animals lived in different times apart from each-other makes classifying them much more difficult than modern organism (that and the fact fact that they are often badly preserved).  

I was aware that Dicraeosaurus hansemanni may have evolved into D. sattleri but I didn't know about the different species of Giraffatitan and Tornieria.  It reminds me of the Morrison formation and how in each zone there are different Diplodocids and some of which may have evolved into others. 

Do you think sauropods had shorter species time spans than theropods and ornithischians?  In the Morrison for example there are certain species like Allosaurus fragilis, Stegosaurus stenops and S. ungulatus, Othnielosaurus consors, Camptosaurus dispar, and Dryosaurus altus that are present in practically every zone, but then you have sauropods like Diplodocus carnegii which is only known from zone 4 and "Brontosaurus" louisae and B. excelsus which are only known from zone 5.  The only Morrison sauropods that seemed to span most of the formation were Camarasaursu lentus and C. grandis.
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
Well there do appear to be 3 species of Giraffatitan but they are currently not separated or named.

Morrison is not really as you say. Allosaurus fragilis, Stegosaurus stenops, etc. are not in all the zones. Allosaurus has different species - fragilis, atrox, jimmadseni, etc. and they differ stratigraphically. But most popular books lump them all into fragilis and act like there is no difference in morphology - they could not be more wrong. Stegosaurus, same way. S. stenops has been split apart into S. sulcatus, S. longispinus, and several others. Also, Hesperosaurus was pulled out of Stegosaurus completely. Most mass-market books leave this out.

So it really doesn't seem to be a hard and fast rule for sauropods alone. The confusing part is how over-lumped some genera are. Camarasaurus included. There is a lot more variation in Morrison genera than most people realize, and many of the specimens are unpublished. It's just that diplodocids are known to be diverse and fast-evolving thanks to detailed work from Tschopp, and I can see the variation in brachiosaurs going similarly fast, but the same is probably true of most other dinosaur groups if somebody were to do a study similarly detailed to Tschopp's on them. It's just that nobody yet has.
Steveoc86's avatar
Looks great! I'd need to refresh myself with the material but I'd got the impression that the nasal seemed 'flatter'' in side view. Unless I've missinterpreted it. It doesn't help not being able to see it in 3d.
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
The odd thing is that the description paper listed this configuration as the side view and the other flatter view as the top view for the nasal... but even if it is flatter in side view, it could also be crushed, as with the Euhelopus nasal... the new Euhelopus skull paper with the CT scans was a real eye-opener to how most of the skull bones were crushed flat. In Sarmientosaurus (which I suspect was a very close relative of Paluxysaurus) the nasals are mostly broken off but the forehead also shows some deep vertical crushing. So there's likely to be some range of interpretation for the nasal arch's height.
Steveoc86's avatar
I think I was swayed by the mounted skull. I disagreed with it's overall shape but I think I assumed they oriantated the nasal more or less correct. When I get time I will probably redo the nasal on mine.
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
Yes, the original nasal wasn't even complete, it looks broken on both ends. This is always the tricky part with skeletals, how much bone do you add on the broken ends of bones? The team that created the mount went as conservative as possible with the skull bones, though this is not always necessarily the best approach. Of course adding too much filler on the ends is also a potential pitfall.

My Paluxysaurus skull used to have an even higher nasal arch but I reduced it after taking a closer look at the shape of the maxillary articulation and using Sarmientosaurus for reference (so now in chubutisaurs the nasal process reaches furthest down in front of the maxilla's upper process, whereas it goes behind it in Giraffatitan and other brachiosaurs). The maxillary articular process actually does not appear too broken, and it's oriented a bit different from in Giraffatitan, though without Sarmientosaurus for reference I probably would have added extra bone onto it using Giraffatitan, Felch Brachio, or Abydosaurus as reference. The whole Paluxysaurus nasal looks worn, even if in some places like the maxillary articulation, that erosion is merely a cosmetic matter of a couple mm...
PeteriDish's avatar
PeteriDishHobbyist General Artist
holy smokes! high fidelity indeed!
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
That's in the works.
ForbiddenParadise64's avatar
Very nice. How tall is this one? 

And this his makes me wonder what your French Monster reconstruction will look like...
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
I would expect the French monster to be very similar, perhaps a bit more robust in the limbs and with a proportionally longer neck.
ForbiddenParadise64's avatar
It seems Franoys is also asking the team for nine measurements so he can do exact comparisons, though he hasn't gotten a reply back yet. He calculated Paluxy's femur )m(I believe holotype) at 1469mm for reference, though he still prefers the official Turiasaurid claim.
Paleo-King's avatar
Paleo-KingProfessional Traditional Artist
That team is doing some annoying things. One of them being the needless secrecy.
anonymous's avatar
Join the community to add your comment. Already a deviant? Log In