gigadino96
Junior Member
Vi ravviso, o luoghi ameni
Posts: 226 
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Post by gigadino96 on Nov 22, 2013 19:28:35 GMT 5
 ^ Uhm...seems that the misterious giant Theropod (here, in Italy, the news will arrive at 16:00) of wich Cau was talking about is Sias. Cool north american Carcharodontosaurid however. |
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Post by Godzillasaurus on Nov 22, 2013 19:30:36 GMT 5
I honestly fail to see how one who is not misinformed would think carcharodontosaurids look THAT similar to tyrannosaurids in physicality.
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Post by creature386 on Nov 22, 2013 19:36:51 GMT 5
Remember that these artworks are not scientific reconstructions, so you should not judge the look of the animal from them.
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blaze
Paleo-artist 
Posts: 766
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Post by blaze on Nov 22, 2013 21:37:56 GMT 5
The models on the game are inaccurate on purpose, their aim is to replicate the official look, not an accurate one.
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Post by theropod on Nov 22, 2013 21:38:36 GMT 5
Siats demonstrates the same thing that Shaochilong and Chilantaisaurus already did, the reign of carcharodontosaurs lasted quite long even in North America and Asia. Perhaps it's merely a metter of time until we find a post-Turonian species... An interesting read: www.research.ed.ac.uk/portal/files/8237163/Brusatteetal2010AsianTheropodReview.pdf@those models: I didn't mean to imply such renditions had or were intended to be accurate. I was just a bit unnerved by the constant aim to give theropods those bunny hands. It's a myth that's very hard to get rid of, the problem being that it comes hand in hand with wrong perceptions about forelimb and whole-body posture and mobility, so in the end the whole animal looks and is unrealistic. btw why exactly are we discussing models from video games here?
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Dakotaraptor
Junior Member
Used to be Metriacanthosaurus
Posts: 193
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Post by Dakotaraptor on Nov 23, 2013 2:48:12 GMT 5
^ Uhm...seems that the misterious giant Theropod (here, in Italy, the news will arrive at 16:00) of wich Cau was talking about is Sias. Cool north american Carcharodontosaurid however. Zanno and Makovicky stated Siats as Neovenatorid, not Carcharodontosaurid. However neovenatoridae family belongs to carcharodontosauria clade though. www.nature.com/ncomms/2013/131122/ncomms3827/full/ncomms3827.html |
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Post by theropod on Nov 24, 2013 17:56:10 GMT 5
btw did anyone else notice the silhouette associated with Tyrannosaurids in the cladogram from Zanno & Mackovicky is actually an Allosaurus?
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Post by theropod on Nov 25, 2013 2:44:20 GMT 5
  The Siats ilium is a minimum of 30% bigger than that of Aerosteon (maximum 51%, median 42%). Pretty impressive, a subadult that's almost as large as the biggest Acrocanthosaurus, or roughly the size of Epanterias... It seems neovenatorids are comparable to allosaurids in terms of robusticity. However, they seem a little more low-slung and particularly long-armed (comparable to the most extreme scope of variation seen in Allosaurus). Neovenator by Scott Hartman→  Allosaurus by Scott Hartman→Any opinions? ---References:Sereno, Paul C.; Martínez, Ricardo N.; Wilson, Jeffrey A.; Varricchio, David J.; Alcomber, Oscar A.; Larsson, Hans C. E. (2008): Evidence for Avian Intrathoracic Air Sacs in a New Predatory Dinosaur from Argentina. PLoS ONE, Vol. 3 (9) pp. 1-20 Zanno, Lindsay E.; Makovicky, Peter J. (2013): Neovenatorid theropods are apex predators in the Late Cretaceous of North America. Nature Communications, Vol. 4 (2827) pp. 1-9 |
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Post by coherentsheaf on Dec 1, 2013 0:14:26 GMT 5
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Post by theropod on Dec 1, 2013 1:21:31 GMT 5
Indeed, it appears its centra in particular are extraordinarily tall and wide, and increasingly so the closer to the pelvic girdle they are (they tend to be more uniform in most theropods).  This and the only slightly procoelous vertebrae, as opposed to the typically more strongly developed condyles of other theropods, may be indicative of a more rigid spine, which would fit together well with presumed greater cursoriality. |
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Post by theropod on Dec 1, 2013 1:45:42 GMT 5
A quote of Blaze's short post on Siat's size from cf The paper does estimate its mass at 3.9 tonnes, there's no mention of total length, but assuming perfect isometry with Acrocanthosaurus it'll be ~10.8m long (~35ft), I'll check with Hartman's Neovenator, that should be a better comparison, but of course, not perfect since Siats is not that complete. edit: I think I'll compare using other parts of the body, comparing with Neovenator using the estimated femur length yields 11.7m in length from tip to tip, that's too big, IMO. edit2: So, the 13th dorsal is 54% longer than that of the holotype of Neovenator, the 5th is 89% longer, removing the bones from the skeletal in the paper (is not that good) and trying to fit them in Neovenator, I got it at something like 55% bigger, it turned up again over 11m from tip to tip... I think this matches up with what I did pretty well. A nice 11-12m...subadult. blaze: I hope it's ok that I copied it here, if not I'll remove it of course! |
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blaze
Paleo-artist
Posts: 766
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Post by blaze on Dec 1, 2013 4:51:11 GMT 5
It's totally ok  |
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Post by coherentsheaf on Dec 1, 2013 7:55:05 GMT 5
Indeed, it appears its centra in particular are extraordinarily tall and wide, and increasingly so the closer to the pelvic girdle they are (they tend to be more uniform in most theropods). I agree. Cau is overzelaous in declaring T. rex more massive than other theropods based on this since more direct volumetric methods yield higher results, with at least the Giganotosaurus holotype being comparable in size to tyrannosaurus (probably not FMNHPR2081 though) from reasonably complete material, so a different biomechanical explanation for the discrepancy is preferable. |
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Post by theropod on Dec 1, 2013 16:15:56 GMT 5
One would expect the same thing he claims to hold true about vertebral centra in the thickness of limb bones, and yet, as I demonstrated based on Acrocanthosaurus and the T. rex MOR 555, methods based on it yield completely flawed results (something the like of that Acrocanthosaurus being less than 60% the weight of the T. rex while they are more realistically about the same weight, as shown in the volumetric analysis of Bates et al. 2009).
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Deleted
Deleted Member
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Post by Deleted on Dec 1, 2013 17:52:36 GMT 5
Indeed, it appears its centra in particular are extraordinarily tall and wide, and increasingly so the closer to the pelvic girdle they are (they tend to be more uniform in most theropods). I agree. Cau is overzelaous in declaring T. rex more massive than other theropods based on this since more direct volumetric methods yield higher results, with at least the Giganotosaurus holotype being comparable in size to tyrannosaurus (probably not FMNHPR2081 though) from reasonably complete material, so a different biomechanical explanation for the discrepancy is preferable. Here's a good one: As Cau himself says on his blog, such a comparison would make you think that Acrocanthosaurus had a mass half that of FMNH PR2081. But he claims that those estimates are in line with those from other methods! Well, let's see what the scientific literature has to say about that: A computational analysis of locomotor anatomy and body mass evolution in Allosauroidea (Dinosauria: Theropoda)The best guess is ~6.177 tonnes, minimum is ~5.569 tonnes, and maximum is ~7.75 tonnes, for the Acrocanthosaurus specimen NCSM 14345. Even the minimum estimate is more than half the mass of FMNH PR2081, which is estimated at around ~8 tonnes give or take. Unless you think Tyrannosaurus reached ~11+ tonnes, which is very, very, very unlikely, this paper supports my disagreement with Cau's comparison. His logic is that the vertebra holds up the weight of the creature, and thus he generalizes that there is a constant ratio between vertebral volume and body mass. Well, the legs hold up the weight more than the vertebra do, yet there's not much of a correlation between limb bone robusticity and body mass. I'm now really convinced that he really is just trying to make Spinosaurus as small as possible. Scott Hartman's reconstructions are much better here since not only do they compare the individual bones, but also the overall body size. Cau can be quite convincing on many other topics, such as the coelurosaurian affinity of Sciurumimus, Spinosaurus being a powerful and fast biter, and that Sigilmassasaurus could have been very similar to Spinosaurus(still not convinced of synonymy due to lack of further evidence), just to name a few. But on the topic of Spinosaurus' hypothetical size, he just kinda seems to falls short to be honest. It would be much better if he focused on the other attributes of Spinosaurus, like well, what's the structure on it's back...(although the smooth outline of the spine in his skeletal seems to indicate a hump or a ridge) |
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