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Post by theropod on Oct 6, 2014 20:59:49 GMT 5
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Derdadort
Junior Member
Excavating rocks and watching birds
Posts: 267 
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Post by Derdadort on Oct 7, 2014 19:34:32 GMT 5
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Post by theropod on Oct 7, 2014 20:28:13 GMT 5
Nope, no idea. But everybody who does sauropod skeletals seems to make his/her work look strange in some regard…
About that diagram, papers are contradicting each other quite strongly on this (I can’t help but guess that they all want to have the most complete giant titanosaur if they find something resembling a skeleton). Osteology of Futalognkosaurus claims it to be almost 70% complete. Based on the diagram, the entire precaudal vertebral collumn, ribcage and pelvis are preserved, so it isn’t that much more incomplete than Dreadnoughtus.
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Post by creature386 on Oct 8, 2014 20:42:52 GMT 5
This is quite amazing. The others are not even close to 50% complete. While Futalognkosaurus was not surprising, Puertasaurus is not even 3% complete. I remember when I and some others joked about a Puertasaurus mummy.… Thanks for posting this! |
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blaze
Paleo-artist 
Posts: 766
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Post by blaze on Oct 9, 2014 0:42:52 GMT 5
I wonder why was Calvo claiming 70% completeness for Futalongkosaurus, it clearly has a lot less bones preserved than Dreadnoughtus once you get down to the numbers though, Dreadnoughtus kind of cheats in the axial bone count as 50 of its 94 axial bones are the tail and the chevrons while the c1-s6 vertebral series of Futalongkosaurus only counts as 30 elements, (this doesn't include cervical ribs which are apparently not preserved in F. dukei).
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Post by theropod on Oct 20, 2014 2:14:14 GMT 5
Derdadort: The neck reconstruction was largely to assist in doing the mass estimate using graphic double integration (GDI). It's easier when in a horizontal plane, plus, most of the neck is missing, so it is difficult to illustrate a neck from multiple views wen the neck is arched. I have been thinking of adding a more "life-like" posture in addition to these to emphasize the fact that I do not consider this an in vivo posture. from here: comments.deviantart.com/1/486665343/3636323282
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Post by creature386 on Oct 20, 2014 16:04:20 GMT 5
RE: Completeness of sauropods, there is one thing I have to add. This picture only looked at how much % of bone types were found. When looking at how much % of bones overall were found, Dreadnoughtus comes close to 45%.
Which means Puertasaurus and such were even less complete than I thought.
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Post by Godzillasaurus on Oct 22, 2014 2:48:31 GMT 5
For the record, the vast majority of prehistoric animals are known from only partial remains (the majority of their bodies are usually drawn based on phylogeny, size of the remains relative to other similar genera, and speculation)
Amphicoelias for example is known only from one single vertebrae, and the same can be said about things like bruhathkaysaurus (so obscured; the only remains are an illium and a tibia, which are both controversial in that they may simply be petrified wood).
Let's face it, studying obscure prehistoric animals is no easy task, because normally your only physical resources are knowledge and your often very limited remains.
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Post by theropod on Oct 26, 2014 1:48:50 GMT 5
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Post by Grey on Dec 16, 2014 4:09:45 GMT 5
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blaze
Paleo-artist
Posts: 766
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Post by blaze on Dec 16, 2014 14:44:36 GMT 5
wow it never crossed my mind to check if all the measurements were consistent, certainly, the possibility of Cope making a typo seems very real, specially when it appears it was common for him to make that kind of mistakes.
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Post by theropod on Dec 16, 2014 21:12:48 GMT 5
Wait, is there any real evidence?
Extrapolated standard metrics in both cases deviate from the actual measurements markedly, and it’s the 1500mm that produced the figure closest to one of the original figures, as well as the figures closest on average. Also there’s a certain consistency in the bias of either set of measurements (one too small, one too large).
Looks like a measurement issue to me (derived from measuring a 2D representation of a 3D object without clearly defined or intelligble reference points).
Assuming Cope’s own schematic was supposed to be consistent with his total height estimate, it would be less than 1.6m tall with the preserved portion measuring just 1.05m, but Cope wrote "no less than 6 feet, and probably more". 1.5m is consistent with that, 1.05m is not, at least if you restore it the way Cope did.
Also what about all the points supporting its size which Carpenter already published years ago? And don’t you think Cope might have checked his height measurements when emphasising the enormous size of the creature, more so than he would do with some mid-sized femur?
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Post by theropod on Dec 16, 2014 22:01:06 GMT 5
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blaze
Paleo-artist
Posts: 766
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Post by blaze on Dec 17, 2014 2:08:21 GMT 5
There's no evidence either way and the paper makes that clear but Cope has a history of misconversions and typos and he seemingly forgot all about the thing as soon as the paper went into publication. That the actual number is 1200mm rather than 1050mm or 1500m is also possible, maybe more so as the resulting measurements are now almost exactly the correct ones. Also, is not as if Cope's drawing were perfect, his A. altus vertebra drawing is too skinny, somewhat idealized and IIRC depicts the preserved transverse process in the opposite side of where it should actually be when seen from the depicted view.
Carpenter doesn't offer any strong points, that Cope never made a correction? maybe he didn't even knew there were errors, he never corrected his mistake with A. altus either, Marsh never questioned the measurements? maybe he indeed had spies that corroborated the thing was real and very big, that the spies also corroborated the measurement... how? measuring it themselves? most likely is that they didn't went that far and his last point is the weakest, "others have taken the measurement without questioning it and so should we".
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Post by theropod on Dec 17, 2014 2:59:53 GMT 5
I think the difference between a 1.5m and a 1m element would be quite readily apparent to any spie, especially someone specifically searching for errors to exploit.
It’s not that I would consider "historical precedence" relevant. It’s that the last simply means that neither of these appear to have found solid grounds based on which to question the measurement.
The alledged typo is probably the most common (and indeed an almost omnipresent) criticism of Amphicoelias fragillimus’ size and far from being a new finding, but frankly it seems like there’s nothing new to support it here, considering the measurements in question deviate even further from the actual figures using any conceivable figure that might result in writing 1500 as a typing error.
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