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Misidentified vertebrae - Gober Chalk, Gober, Texas


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ziggycardon

I recently purchased this vertebrae which was sold as a mosasaur (Clidastes) vertebrae.
I wasn't convinced that the vert was Mosasaur (or even marine reptile for that matter) in origin when I bought it, I simply bought it because I thought it was a nice looking vertebrae. But now I thought I might give it a shot to try and get an ID on this thing. 
It was found in the Gober Chalk, Austin Group, Gober, Fannin County, Texas, USA and dates back to the Campanian, Cretaceous (± 80 mya). 

I don't really know what the vertebrae could be honestly, I don't believe it to be Mosasaur in origin or any other marine reptile like Plesiosaurs or Pliosaurs.

 

I have been searching to see if it might belong to a cretaceous giant sea turtle like Archelon or something but I can't find really find any pictures of sea turtle verts to compare with.

 

When I posted the vertebrae in my collection topic some members were inclined to point toward the vertebrae being mammalian in origin, but due to the size that would mean it probably isn't cretaceous in origin due to it's large size.

 

On 3/4/2021 at 8:46 PM, JohnJ said:

 

This piece looks different from mosasaur vertebrae in texture, color, and proportions for Texas.  Typically, the neural canal would be full of hard matrix and not as large.  There also seems to be cancellous bone exposed that looks more mammal-like.

 

On 3/4/2021 at 9:43 PM, pachy-pleuro-whatnot-odon said:

Yeah, I too have seen the vertebra for sale. Wasn't too convinced then either, or else I'd have bought it. Quite telling, I think, that no photographs of the axial views were included in the sale... Now I haven't seen too many matrix-free mosasaur vertebrae - at least not with the neural arches and spinous processes intact - but when seeing the actual views, I also very much doubted it being a mosasaur vertebra: it looks nothing like the cervical or dorsals I have in my collection, not like the caudals I've seen. With the wide neutral canal and high position of those flaring processes, it indeed looks most mammalian...

 

So I made some more photos to get a better image of the vertebrae, I made some close ups a well of the bone structure and of the some of the places where you can clearly see remains of a chalk like matrix stucking to the bone. 
So I was hoping if someone might be able to put an ID on this thing and maybe if it is mammalian in origin where it might originate from should it not be cretaceous.

 

Thank you in advance! 

 

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ziggycardon

Forgot to include the photo's, so here they are

161606741421725254.jpg.45d44ca7242aea1d92133dbac99f44c4.jpg

2104351685_161606741421725254(1).jpg.9a7440a703a19a34132a4f46e3bc4df9.jpg

185822380_161606741421725254(2).jpg.26f0d0bce4bd87ddc4102b9e3717f4d7.jpg

713949682_161606741421725254(3).jpg.37a9aee870c2c86a8a5a2667f02f9d6d.jpg

1595890039_161606741421725254(4).jpg.a4589e767e6f9d898c12e6a83c416dd4.jpg

161606741421725254 (6).jpg1620474889_161606741421725254(5).jpg.8db5058e6b0e97a173023138a204362c.jpg

 

479504734_161606741421725254(7).jpg.d2490933f5ae72df3a030ba8f65d2000.jpg

475577253_161606741421725254(8).jpg.9cbf9cce3d666283fb791c435f8940c8.jpg

1889038141_161606741421725254(9).jpg.236ce45ca2d6d9f05eda0ceb18783dae.jpg

1017770800_161606741421725254(10).jpg.dab7c11cca8ff20d40943491e848b888.jpg

752417065_161606741421725254(11).jpg.3957f3669c55eea418c02abaaa2e1de9.jpg

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I agree.... this does not look mosasaurian.  I hope someone else can ID it.  

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Fossildude19
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pachy-pleuro-whatnot-odon
39 minutes ago, ziggycardon said:

479504734_161606741421725254(7).jpg.d2490933f5ae72df3a030ba8f65d2000.jpg

475577253_161606741421725254(8).jpg.9cbf9cce3d666283fb791c435f8940c8.jpg

 

So, the first step in the process of identifying this piece would be to determine whether the vertebra is procoelous or opisticoelous. In this, the direction the dorsal process atop de neural arch pointed in is determinative. Unfortunately, that's where the shape of the neural arch and the apparent plastic deformation are throwing me off a bit. However, the way the dorsal process has broken off - with the higher remaining part on the concave end of the centrum and more seeming to have broken off on the convex end - suggests that the convex end of the vertebra was load-bearing for the dorsal process, and thence that the dorsal process originally pointed from concave to convex, This, then, would advocate for the vertebra being procoelous - which, coincidentally, is a more common condition than opisticoelous.

 

2000px-Centrum_Morphology_svg.thumb.png.85d260142365deb284a7e416eccfc262.pngSource

 

 

 

 

 

 

 

 

 

 

 

 

 

821365669_Centrummorphologywithexamples.thumb.jpg.02e4c4b6890cc9e23acf5d24631a9953.jpgSource: @diginupbones

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

As such, procoelous vertebrae certainly do fall within the realm of crocodiles, snakes, varanoids and mosasaurs, with the current vertebra's elongate shape, moreover, matching those of the latter three groups (as well as that of marine crocodyliformes). The strong keel and wide, triangular/trapezoidal shape of the neural canal are not typical of mosasaurs, though, as far as I'm aware, and the latter feature much rather recalls that found in crocodilian vertebrae:

 

2123029932_CrocodilevertebraBouxwiller.thumb.jpg.76c751a707d1f81745d881bbe63e8b4d.jpgCrocodile vertebra from Bouxwiller

 

 

 

 

 

 

 

 

 

 

 

As far as I'm aware, however, the structures on the neural arch do not match those of crocodylians, as in crocodylians they start lower on the concave side and end higher on the convex side. Rather, the current vertebra exhibits the reverse configuration, one more reminiscent of mosasaurs, if it weren't for the fact that the neural arch is so tall. As such, I have no idea what the vertebra could be from, but certainly do see how it got classed as a mosasaur.

 

If the vertebra is that of a mosasauroid, though, people like @KansasFossilFinder, @Indagator or @jnoun11 should be able to help out. If, on the other hand, it's a crocodilian vertebra, @caterpillar might be know.

 

An enigmatic piece... :zzzzscratchchin:

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I don't think this is Cretaceous in age or reptile.  Based on the open cell cancellous bone, large and clear neural canal, and subtle 'ringed' bone structure on the centrums, I think it's mammal.  It may be Pleistocene, and it could be horse.

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pachy-pleuro-whatnot-odon
13 minutes ago, JohnJ said:

Based on the open cell cancellous bone, [...]

 

And there's that too. Forgot to mention. Doesn't look particularly osteosclerotic, thus almost certainly not a marine reptile.

 

But, as I don't have any experience with mammals, that's about all I can say.

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caterpillar

Not a croc for me

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Indagator

I dont think it is a giant sea turtle either. The size is an issue. I will check a paper tomorrow if i can find a match.

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ziggycardon
Posted (edited)

Thank you all for your replies! 
 

On 3/19/2021 at 2:15 AM, jpc said:

I think horse cervical is a good place to start looking.  

 

Have a look at this site:

https://www.imaios.com/en/vet-Anatomy/Horse/Horse-Osteology-Illustrations

The vertebrae shares lots of similarities with the C6 vertebra of a horse.

The next step is probably determining it's age and the deposit where it might originated from as it bears traces of chalk matrix, I hoping some of our Texan members might be of assistance in that matter :) 

Edited by ziggycardon
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16 minutes ago, ziggycardon said:

the deposit where it might originated from as it bears traces of chalk matrix,

 

I wouldn't place too much stock in trace amounts of chalk matrix on items from the Gober Chalk or North Sulphur River.  Redeposited specimens, from modern to Pleistocene, can have that Cretaceous slurry in every crack and crevice.  

 

If it is not significantly mineralized, you might try a burn test to rule out being a recent bone.

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ziggycardon
Posted (edited)
11 minutes ago, JohnJ said:

 

I wouldn't place too much stock in trace amounts of chalk matrix on items from the Gober Chalk or North Sulphur River.  Redeposited specimens, from modern to Pleistocene, can have that Cretaceous slurry in every crack and crevice.  

 

If it is not significantly mineralized, you might try a burn test to rule out being a recent bone.

Thank you,

The bone in definitely entirely mineralized, as it really feels rock solid and weights a lot for it's size. 
It's also a lot heavier in comparison than all my other pleistocene stuff from the North Sea and Florida.

Edited by ziggycardon
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