So, no Kem Kem dromaeosaurids after all?

[BirdsAreDinosaurs]

Hi all,

 

I just recently had the time to thoroughly read through this recent paper, which describes, amongst other things, how machine learning was used (in combination with other techniques) to identify a possible Deltadromeus tooth. The authors also suggest the presence of a second noasaurid species in the Kem Kem beds, based on a small sub-adult partial vertebra.

 

In the discussion, the authors discuss individual teeth found in the Kem Kem beds that were previously referred to Dromaesauridae by Amiot et al. (2004), Richter et al. (2013), and Ibrahim et al. (2020a). The authors believe all of these teeth do in fact not belong to Dromaeosauridae. They say some are most likely abelisaurid, and others noasaurid (those with strongly distally recurved crowns and those with a non-serrated mesial carina and/or a faint constriction between tooth and crown). All of the dental features used to refer Kem Kem teeth to Dromaeosauridae, are in fact also present in noasaurids and juvenile abelisaurids.

 

To be honest, I never really believed the teeth described in these older papers belonged to Dromaeosauridae. Having said that, there are still some tooth types from the Kem Kem beds that have never been described in scientific literature, which are "dromaeosaurid-like". For example, the ones in Troodon's overview having a twisted mesial carina. However, when you look at lateral teeth of the noasaurid Masiakasaurus, some also have a twisted mesial carina.

 

I think there is still a possibility that some of these small dromaeosaurid-like Kem Kem teeth are in fact dromaeosaurid, but it is quite likely that they all turn out to be noasaurid or abelisaurid. What do you think?

 

 

[rocket]

I always have a problem with determining a raptor only by using the teeth. So many look „similar“, and from a lot of the only some teeth are known. But the teeth from the upper jaw, the lower jaw, frontteeth, sideteth and so on are ofter different. We need lot of complete skulls in all ages, what we do not have. „Dromaeosaurid-type“ will be o.k., because it means „looks like, but could be not“. This includes other possibilities