Moroccan Theropod Teeth Confusion - Deltadromeus, Dromaeosaur & Carcharodontosaurus

[AJ Plai]

Delta, Dromie and Carch are some of the most commonly offered by dealers and collected by many enthusiasts, but I am surprised to find that little has been written about how do you really distinguish these three teeth from one another, especially when they are in small size - in this case I am refering to 1" and below size where the 3 of them look very similar to the untrained eyes. This is especially even more complicated when it comes to Deltadromeus agillis tooth which from what I gathered, shouldn't really technically be accepted to really exist, and should be ideally labeled loosely as Moroccan theropod, yet they are very common in the collectors market, but when asking how can you really tell if they are not Moroccan dromaeosaur tooth or simply a young Carcharodontosaurus tooth, nobody seem to be able to conclusively tell.

The reason I am creating this post asking this question is because I just acquired a couple of new small Moroccan teeth that although have been labeled as Deltadromeus, but I can't be certain if they are really Dromaeosaur or young Carch teeth:

Specimen A:

Specimen B:

Any theropod experts here could give insight into how to identify and differentiate these troublesome teeth would be appreciated and I think many new collectors and enthusiasts of Moroccan dinosauria would find such insights and knowledge very useful. Thx.

Edited May 15, 2015 by AJ Plai

[AJ Plai]

This is another tooth of mine that is labeled as Deltadromeus tooth, it is of considerably larger size than the above 2 specimens (at more than 2.5") so that should rule out the possibility of it being a dromaeosaur tooth but could still potentially be Carcharodontosaurus tooth:

Specimen C:

[Troodon]

Hi AJ

Good question and you are correct very little information out there on Moroccan teeth. You have to wonder how sellers make informed decisions on ID's.

Let's address Dromaeosaur teeth. The best way to ID these teeth no matter what the locality is that they are typically recurved, small (typically <1 inch (2.5cm)) very compressed and there is a distinct difference between the interior and exterior serrations. The interior ones are much larger and you easily can see the difference. If the serrations are the same its not Dromaeosaur. I do not see any with your three specimens.

"Abelisaurid-like" teeth (your "B") has been studied but not described. The teeth are very compressed, the exterior (mesial) side is strongly curved, with the curvature beginning near the midpoint of the crown. The interior(distal) side exhibits almost no curvature; instead it is straight from the apex to the base of the tooth. There is only a small difference in size between the denticles of the mesial and distal surfaces. So until a skull/skeleton is found with teeth these will remain

a mystery.

Deltadromeus is another mystery tooth. Again no skull material with teeth has been found so there is no way to ID this species. Teeth that are not ID'd has Carcharodontosaurus may be this but are more appropriately identified as theropod indeterminate and not Deltadromeus. The current thinking is that Deltadromeus is a type of midsize Ceratosaur so if that the case your specimen C would be much to large.

Your specimen A & C become more problematic and are difficult to ID because of the lack of comparison teeth. Small teeth are that about equally wide and high are easier to identify as Carch but yours does not fit that bill. My guess is that both are Carch and C is just a positional tooth from the front of the jaw and because it does not fit your typical flat dentary tooth why its called Deltadromeus.

The Kem Kem theropod are poorly understood and caution needs to be taken when buying these teeth.

Edited May 16, 2015 by Troodon

[AJ Plai]

Thx, for the very detailed and insightful information on Moroccan theropod teeth.

[Welsh Wizard]

Hi Troodon

Thanks for such an interesting a thorough reply. It never ceases to amaze me how such small differences in teeth or bones can help tell the difference between different dinosaurs.

All the best

Nick

[Eocenecarnage]

All three are Dromeosaur teeth (Deltadromeous is a dromeosaur).

[Troodon]

Why do you think all three are Dromaeosaurus? Theropods from Morocco are poorly understood because there has not been enough fossilized remains found with skulls. Deltadromeus teeth have not been published in a paper for a similar reason. Some believe this dinosaur is a Ceratosaur but this will better understood with new discoveries.

Edited July 27, 2015 by Troodon