Indeterminate Kem Kem Theropod Tooth

[Omnomosaurus]

It's been a little while since I've popped in to the fossil world properly, but I finally came across another unusual little theropod tooth from the riddle that is the Kem Kem, and just had to pick it up.

 

The overall size and a bit of chunkiness going on here discounts the theorised dromaeosaurid(s) from the locality, and the recurved distal edge doesn't scream abelisaurid. Nothing about it particularly says carcharodontosaurid either, and I can't find a clean match with the morphologies of @Troodon's id guide, though 'morph type 3' is possibly the closest.....so anyone got any thoughts?

 

There's a very strong displacement of the distal carina and the mesial carina extends approx. ⅔ down the mesial face of the tooth. The cross section is oval in shape, with no "pinching" at the base.

 

There are also no interdental sulci or apparent enamel wrinkling (thought the enamel is worn, so it's a little hard to tell).

 

Measurements:

 

CH: 21mm

CBL: 8mm

CBW: 5mm

 

Serration count (midline): 

 

Mesial: 5/1mm

Distal: 3/1mm

 

Labial face (?)

 

Lingual face (?)

 

Mesial face

 

Distal face

 

Cross section (anterior of the tooth is oriented upwards)

 

Quick scale reference

 

Denticles (distal carina)

 

Denticles *worn* (mesial carina)

 

Thanks in advance, peeps!

[Troodon]

Nice pickup and I agree not Dromaeosaurid like.  Any chance its a juvie version of your Carch Pre-Maxillary tooth?  Otherwise its an indeterminate anterior dentary tooth. 

[Omnomosaurus]

2 minutes ago, Troodon said:

Nice pickup and I agree not Dromaeosaurid like.  Any chance its a juvie version of your Carch Pre-Maxillary tooth?  Otherwise its an indeterminate anterior dentary tooth. 

 

Thanks! It's a possibility; they both have that same strongly displaced distal carina.  Good to know its position as anterior dentary, thanks for that Troodon.

 

I've still yet to come across any other pre-maxilliary Kem Kem teeth to do any further comparisons on the topic.

[Troodon]

5 minutes ago, Omnomosaurus said:

I've still yet to come across any other pre-maxilliary Kem Kem teeth to do any further comparisons on the topic

I have yet to see any but unless it fits the classic D shape or your tooth"s morph not sure I would recognize one.   I do have some nice Pre-maxillary teeth of K K Abelsaurids (Rugops like)

[Omnomosaurus]

8 minutes ago, Troodon said:

I have yet to see any but unless it fits the classic D shape or your tooth"s morph not sure I would recognize one.   I do have some nice Pre-maxillary teeth of K K Abelsaurids (Rugops like)

 

That's probably my trouble then, I'm far less experienced in knowing what to look for!

 

I was recently looking at the 2019 paper on theropod teeth, and it's interesting that all members of Carcharodontosauridae seem to have consistency in the length of their mesial carina across the entire dentition (Acrocanthosaurus being the only one with mesial carina not reaching the cervix), so if that premax tooth of mine belongs to Carcharodontosaurus, then that would seem to make it the only member of the family with different features between the mesial-most teeth and the rest of the dentition.

 

Are the abelisaur premax teeth in your collection threads; I'd love to have a look at them?

[Troodon]

Yes I was very surprised when Christophe identified it as Carch for that reason.  We know very little about their dentition hopefully one day some of these teeth will be published..  

 

Here is my rooted Premaxillary Tooth.  Have a few shed teeth but no photos.

[Omnomosaurus]

19 minutes ago, Troodon said:

Yes I was very surprised when Christophe identified it as Carch for that reason.  We know very little about their dentition hopefully one day some of these teeth will be published..  

 

Here is my rooted Premaxillary Tooth.  Have a few shed teeth but no photos.

 

Yeah, I do wonder if he was playing it safe going with Carch, since he didn't sound 100% as committed as he could have been. It makes more sense to show you exactly what Christophe had to say in his own words:

 

 

I was very impressed with how much detail he went into to explain his thought process on finding the id.

 

That's an absolutely beautiful abelisaur tooth you have! I certainly haven't come across any like that in the last year of hunting; especially one so well preserved and rooted!

[Troodon]

Thanks, Pretty fortunate to get the tooth.

 

It looks like a pretty strong statement on that tooth.   I'm sure he has the opportunity to see these other teeth so he's dealing with a lot more information than we have.    

[Omnomosaurus]

38 minutes ago, Troodon said:

Thanks, Pretty fortunate to get the tooth.

 

It looks like a pretty strong statement on that tooth.   I'm sure he has the opportunity to see these other teeth so he's dealing with a lot more information than we have.    

 

Yes, bet that kind of quality tooth doesn't come around very often!

 

Very true, it was the "would not be surprised" statement at the end that made me wonder. Certainly can't argue with his explanation though!