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Post by Grey on Sept 13, 2014 7:59:18 GMT 5
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Post by theropod on Sept 13, 2014 14:04:26 GMT 5
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Post by theropod on Sept 13, 2014 14:28:10 GMT 5
www.skeletaldrawing.com/home/theres-something-fishy-about-spinosaurus9112014qilong.wordpress.com/2014/09/12/the-outlaw-spino-saurus/theropoddatabase.blogspot.de/2014/09/spinosaurus-surprise.htmlI’m beginning to see a pattern here. I’m afraid we’re gonna get a flood of quadrupedal restorations, when the animal was probably not capable of, or needed, quadrupedalism. Headden: " As it is, none of the caudal vertebrae seem to be anterior further anterior than about half of the tail’s length, assuming about 50 caudals.
[...]A quadrupedal spinosaur? I think not. Biomechanically, the forelimbs wouldn’t allow it, and the proportions done either. This doesn’t mean the animal wasn’t adapted for wading through muck and along the marshy shores of an ancient sea. Most likely it could swim, but I’d imagine so could most theropods so this is hardly surprising. Was it some predatory hippo? More croc-like thab we imagine? Probably not." Hartman: "As it happens you can use ImageJ
or Photoshop to check the linear proportions of those elements with
their respective measurement tools, and here is where something fishy
happens, as the ilium in the reconstruction from the paper is much too
small relative to the vertebrae from the same specimen. In fact it needs
to be increased about 27% (e.g. x 1.27) to match the published length.
And it's not just the ilium that is wrong; the rest of the pelvis and
the entire hindlimb is off, and they are off by about the same amount,
suggesting it's the reconstruction and not the measurements that are in
error."
Claims that a dinosaur able to swim also appear unsubstantiated, other theropods and non-theropods have been proposed to be suited for swimming before, and even theropod swim tracks have been discovered: www.academia.edu/3257943/A_new_Early_Cretaceous_dinosaur_track_assemblage_and_the_first_definite_non-avian_theropod_swim_trackway_from_ChinaIt would also be pretty odd if other theropods could not swim. After all, it doesn’t take semi-aquatic adaptions to do so. In fact most have a density considerably lower than water, swimming shouldn’t be much of a problem for them. Of course this is by far the best case for adaptions towards an aquaticlifestyle in a non-avian theropod, but that doesn’t even necessarily mean it was a good swimmmer. The dense bone structure is a link to hippos, which don’t swim at all.
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Post by theropod on Sept 13, 2014 22:41:21 GMT 5
According to this this→ there is going to be a more detailed description of the specimen: Although a detailed monograph describing "Spinosaurus C" is currently in preparation (Maganuco, pers. Com) so for now it is not possible to investigate many questions, from the information published by Ibrahim et al. (2014), you can already make some comparisons with different theropodi found in the Cenomanian of North Africa. |
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blaze
Paleo-artist 
Posts: 766
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Post by blaze on Sept 14, 2014 0:49:02 GMT 5
Penguins have solid limb bones like hippos, they do swim.
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Post by spinosaurus1 on Sept 14, 2014 1:01:42 GMT 5
same with grebes, loons and Cetacea. I may be wrong, but wouldn't it be more accountable if the animal can provide the proper propulsion to negated it's overall body density? hippos do not have any proper adaptions for the propulsion required to swim
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Post by theropod on Sept 14, 2014 1:54:47 GMT 5
Penguins have solid limb bones like hippos, they do swim. Hence the "not necessarily". It depends whether the body plan and habitat were such that they required/faciliated swimming. That’s obvious in the case of Hippos and penguins, but less obvious with Spinosaurus. It doesn’t strike me as adapted for swimming in the way a penguin or whale is, but considering elephants and other non-avian theropods can and do/did swim I’d presume it likely had the same capability, although not necessarily to an exceptional degree. My point is that most theropods could swim, probably even quite easily–so the mere ability to swim isn’t really exceptional, even though the adaption for a semiaquatic lifestyle is. Spinosaurus’ dense bones would give it greater freedom of movement under water (like in a hippo or penguin), but they would also make staying afloat more difficult, so how well it could actually swim isn’t sure, and whether it did isn’t either. If I’d have to guess I’d say that Spinosaurus could swim with the help of its tail and hindlimbs, but didn’t have to do so most of the time due to its sheer size and its habitat primarily consisting of comparatively shallow water. |
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Post by theropod on Sept 14, 2014 20:31:49 GMT 5
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Deleted
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Post by Deleted on Sept 15, 2014 16:08:40 GMT 5
I just read both the main paper and the supplement carefully, twice actually, searching for anything about the shape of the dorsal spine, and I have not found a single thing in it that refutes the placement of the posterior holotype spine as an anterior caudal, nor have I seen it providing any arguments or reasons on why they placed it as the last dorsal.
They don't even cover that topic in the paper.
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Post by theropod on Sept 15, 2014 21:52:22 GMT 5
Hopefully we are going to see an actual description of the material published soon, along with a few actual anatomical details and explanations on their interpretation.
So far I don’t find what they put forth to support their interpretation of the dorsal shape very compelling–not difficult since there didn’t seem to be anything.
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Post by creature386 on Sept 16, 2014 18:00:34 GMT 5
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Deleted
Deleted Member
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Post by Deleted on Sept 16, 2014 18:11:06 GMT 5
It's actually about the NatGeo painting not being that original, not about the dinosaur itself. |
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Post by creature386 on Sept 16, 2014 19:36:37 GMT 5
I know very well what this is about, I just wanted to post it because it is one of their few posts that are not about sauropods. And it was nice to see that Matt agrees with Hartman.
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Post by theropod on Sept 16, 2014 20:34:17 GMT 5
It's actually about the NatGeo painting not being that original, not about the dinosaur itself. Well, that's some valid criticism too, although on the media campaign and not the research. But it highlights how much the media and exhibits tand to overhype the novelty of new findings, especially in this case. I like the artistic style of the new Spinosaurus reconstruction, even though obviously some anatomical details don’t seem sound, but it’s getting too much, especially considering the issue Wedel pointed out. I wouldn’t call it plagiarism. This is simply a very natural scenery for a Spinosaurus. But people should stop acting as if there was something radically new about it (because the actual new things are not even visible), because there is nothing new about most of what is shown except the color scheme (and a pair of inaccurate legs). |
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Post by theropod on Sept 17, 2014 0:07:42 GMT 5
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