Deinocheirus remains finally described!

[theropod]

The holotype of Deinocheirus mirificus was collected by the 1965 Polish–Mongolian Palaeontological Expedition at Altan Uul III in the southern Gobi of Mongolia1. Because the holotype consists mostly of giant forelimbs (2.4 m in length) with scapulocoracoids2, for almost 50 years Deinocheirus has remained one of the most mysterious dinosaurs. The mosaic of ornithomimosaur and non-ornithomimosaur characters in the holotype has made it difficult to resolve the phylogenetic status of Deinocheirus3, 4. Here we describe two new specimens of Deinocheirus that were discovered in the Nemegt Formation of Altan Uul IV in 2006 and Bugiin Tsav in 2009. The Bugiin Tsav specimen (MPC-D 100/127) includes a left forelimb clearly identifiable as Deinocheirus and is 6% longer than the holotype. The Altan Uul IV specimen (MPC-D 100/128) is approximately 74% the size of MPC-D 100/127. Cladistic analysis indicates that Deinocheirus is the largest member of the Ornithomimosauria; however, it has many unique skeletal features unknown in other ornithomimosaurs, indicating that Deinocheirus was a heavily built, non-cursorial animal with an elongate snout, a deep jaw, tall neural spines, a pygostyle, a U-shaped furcula, an expanded pelvis for strong muscle attachments, a relatively short hind limb and broad-tipped pedal unguals. Ecomorphological features in the skull, more than a thousand gastroliths, and stomach contents (fish remains) suggest that Deinocheirus was a megaomnivore that lived in mesic environments.

www.nature.com/nature/journal/vaop/ncurrent/full/nature13874.html#supplementary-information

Not an obligate herbivore as we used to think, but an omnivore. And its truly strange!


It’s really bulky, like a therizinosaur, and it has that long, duck-like snout and massive lower jaw:


That skull is over a metre long. I get an axial lenght of almost exactly 10 times the maximum skull lenght, i.e. about 10.6m, so its rather short, but robust.

[Infinity Blade]

Hooray for the camel-duck-therizinosaur thingy! This animal looks really cool.

[theropod]

It does, right! Far more interesting than a boring upscaled Ornithomimus!

[Infinity Blade]

Damn right.

[Fragillimus335]

I get lengths of ~12-12.5 meters based on the 994cm humerus.

[blaze]

The limbs might be bent in the z axis in the skeletal, the femur of the larger specimen is supposedly 132cm long but scaling it at that size results in an skull 112cm in premaxilla to quadratojugal rather than 97cm and the humerus at 95cm rather than 100cm.

[Deleted]

Not open access...




Does someone have the paper?

It would be appreciated if someone sent it in an email to [e-mail]

[theropod]

I’m adding my mail adress to that list if anyone has access, I haven’t found the paper itself either. However at least the supplement is accessible.

[Deleted]

Oct 23, 2014 22:38:01 GMT 5 theropod said:

I’m adding my mail adress to that list if anyone has access, I haven’t found the paper itself either. However at least the supplement is accessible.

I have the paper now and have been reading it for a while, I'll send it to you.

__________

I get an axial length of around ~12.4 meters for the holotype specimen, scaling using the ~93.8-centimeter humerus.

[theropod]

Thanks! How did you get it?

[theropod]

© John Conway, 2014: johnconway.co/deinocheirus-mirificus

[theropod]

axial lenght:
skull lenght (pmx-q)=97cm==>10.76m TL
femur lenght=132cm==> 12.44m TL
tibiotarsus lenght=118cm==>12.45-12.75m TL (depends on whether proximal extend of cnemial crest is included)
humerus lenght=100cm==>12.98m TL
pubic boot lenght=50cm==>~13.05±0.45 TL
pubis lenght=114cm==>11.29m TL
ischium lenght=111cm==>11.67m TL
scalebar=88cm==>12.02m TL (1058px)

skull/femur (skeletal)=0.844
skull/femur (measured)=0.735

All pertain to MPC-D 100/127

I realise there could be prespectivic distortion, but that should, if anything, make stuff that is based on the femur or tibia (which are closer to the viewer than the skull, measured in the transverse plane) smaller, while it ends up larger. The humerus is the exception, as it’s actually fully possible, albeit not very likely, to be quite far from parasagittal.

Something is strange here.
But I have to applaud the authors for including their skeletal as in a vector format and hence making it scaleable. They also labeled their measurements remarkably well when it comes to the vertebrae and skull, although that sadly does not extend to the appendicular elements (for example femur lenght, or ilium–in what plane is the latter measured? Perpendicular to the sacrum, or vertically as to fit the skeletal. And is the former maximum lenght?).

[blaze]

I sent it to him but I don't know if he had got it earlier.

[Deleted]

Oct 24, 2014 3:24:52 GMT 5 blaze said:

I sent it to him but I don't know if he had got it earlier.

I only got it when I received your message, well, you know now.

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theropod: Deinocheirus skeletal in vector form? Where can you get this? I had to use Inkscape to give it a crisp outline like what I always do when I wanted to enlarge a low-resolution skeletal.

And have you seen how they feathered their Deinocheirus reconstruction? I suspect that the typical "large body size = less feathers" reasoning has been used here.

[theropod]

I’ve seen the life reconstruction. I’ve got no problems with the "large body size=>smaller & fewer feathers"-reasoning, but I don’t really like the sharply delimited patches of large feathers opposed to completely featherless skin on the rest. I think if they existed, differences in feather size and density would be more gradual.

Just import the first page of the PDF into inkscape and you get the whole page, including the skeletal in vector form, then you can render it in any size you want or directly export an SVG. Or, if you prefer, you can import the page into GIMP (I presume PS has the same feature) in the desired resolution.
It luckily wasn’t embedded as a bitmap image as is so often the case. Instead they made use of the skeletal already existing (presumably having been made) as a vector image and the possibility to directly include vector graphics in pdfs.

Attachments:

deinocheirus.svg (820.66 KB)