spinosaurus vertebra?

[Still_human]

What do you guys think?

Apparently from Oued Zem, Morocco.

[Troodon]

What size is it.  Yes it might be a Spinosaurid cervical.  I dont think its Sigilmassasaurus but the ventral side diagnostic area is poorly preserved.  It's not from that locality but Kem Kem.  Preservation is right for KK...and there are no Spino's in Maastrichtian deposits.

 

@LordTrilobite. What do you think

[LordTrilobite]

Yup that's a Spinosaurid posterior cervical vert from Kem Kem beds.

I would say this is most likely C7 or C8. In the back of the neck judging from the slenderness/fattness, but not the last cervical.

 

Cervical and anterior dorsal vertebrae for Sigilmassasaurus and Baryonyx. Note that the atlas/first cervical is not present in these images. So there are 10 cervicals and 3 dorsals visible.

 

The one area that is the best for identification is partially missing. On the ventral side there should be a posterior triangular rugose plateau if it's Sigilmassasaurus. That feature is not present on Spinosaurus.

There is a ventral keel, but it's not very pronounced. As I understand it, Spinosaurus only has this keel in the back of the neck and nowhere else on it's vertebrae. Sigilmassasaurus has this keel on all it's cervical vertebrae and anterior dorsals. The rest of the dorsals are unknown but I've seen dorsal spinosaurid vertebrae with keels which might be Sigilmassasaurus as well.

The keel does not seem to end in a rugose/rough plateau.

 

Cervicals 6 and 8 for Sigilmassasaurus.

 

Mid cervical of Spinosaurus from my collection. Likely C5 or C6.

 

So I would say this is more likely Spinosaurus than Sigilmassasaurus. If we consider the genus Spinosaurus to be valid in Morocco that is.

And again, most likely the back of the neck, probably cervical 7 or 8.