Whose vertebra is this ?

[Brevicollis]

Hello, today I picked up this neat little vertebra from the Kem Kem beds at my local fossil fair, and now I just need an ID for it.

 

It seems to not really match Spinosaurids or Carcharodontosaurids in my opinion, as it seems way to small to be from them, or the shape is wrong.

So maybe a Crocodile vertebra ? Also, whilst cleaning it a bit, I uncovered two holes on the underside, which are, according to my research, found in Plesiosaur verts ?

So I would consider a Polycotylid or Leptocleidid another possibility, thanks for any answers !
 

Also, might it be possible to tell which part of the spine this one belonged to ?

It measures 4.5 x 4cm.

 

[rocket]

might be Plesio

[jpc]

last photo.... two holes on the bottom... rocket nailed it... plesiosaur.  

[pachy-pleuro-whatnot-odon]

Definitely plesiosaur, and if from the Kem Kem officially supposedly leptocleidid. Recognisable from the subcentral foramina, as Frank and JP mentioned. However, the heart-shaped centrum and even the shape of the dorsal neural arch attachment site are good indications of this being plesiosaur. The one thing that confuses me, though, is the preservation, as that's nothing like the preservation on my vertebra, supposedly also from the Kem Kem...

 

 

 

 

The one on the left, with the red overtone and red matrix is from the Kem Kem, the more light-grey coloured specimen is from the phosphates. Leptoclidid tooth from the Kem Kem included in the last photograph.

[pachy-pleuro-whatnot-odon]

I just checked to see what bone material is mentioned by Bunker et al. (2022) in their publication on the Kem Kem leptocleidids. And while it does seem possible for the bone to be preserved in a more heavily mineralised form with a deeper red colour, I still find the preservation on your specimen surprising, and more in-line with what I've seen from the UK, such as Weymouth. Compare to the materials below:

 

 

Cervical and pectoral vertebrae (left), dorsal vertebra (right)

 

Left humerus

[Brevicollis]

Hey Alex, are there any limestone formations known in the Kem Kem group ?
I found some very soft limestone bits on this vertebra, so I thought it might be possible to narrow down its origin formation ?

[pachy-pleuro-whatnot-odon]

Unfortunately, I don't think the presence of this limestone in and of itself would be able to provide additional insight on provenance. You'd need to do a much more in-depth petrographic analysis for that, looking at the different minerals present in the matrix, their proportions, sorting, rounding, etc., if not outright resorting to isotope analysis.

 

At the same time, based on Ibrahim et al. (2020), it does look like these remnants may be useful in dating the piece strategraphically to the upper part of the Continental Intracalcaire, a limestone deposit close to the Late Cenomanian/Turonian boundary that forms a carbonate platform that can be correlated to the carbonate deposits of the fully marine Akrabou Formation from which the so-called Asfla or Goulmima fossils (plesiosaurs and the basal mosasaur Tethysaurus nopscai) are known. This may also explain the greater degree of similarity in preservation to fossils from those localities versus my specimen...

Edited December 26, 2024 by pachy-pleuro-whatnot-odon

[Brevicollis]

It appears like there is a high iron content, as there is a piece of rust on one side, and also a lot reddish spots, likely dyed by the iron contents of it.

However, there are no traces limestone on this side of the vertebra, so could it be that this vertebra could have originated from the toppest layer of the Kem Kem group, and the deepest layer of the limestone platform on top of it ?
 

EDIT: I just spotted a tiny bit of limestone on the side of the vertebra that I've said that did'nt have any traces of it.

Could it still be from the toppest layer of the Kem Kem group, and the deepest layer of the limestone platform on top of it ?

Its still preserved like most Kem Kem fossils, a lot of sand is still sticking to it, but there is also this weird limestone present. Both things together I have never seen before on one Kem Kem fossil before.

Edited December 27, 2024 by Brevicollis
I forgot to add the pictures

[pachy-pleuro-whatnot-odon]

Hard to say without clear provenance and/or a sufficient comparison collection to match preservation against. While certainly exciting to speculate about these things, I don't think anything can be said about just a single sample that, moreover, is of an undiagnostic specimen.