็hell Creek Dromaeosaur Teeth And Baby Tyrannosaur Teeth - How To Distinguish Them Apart?

[AJ Plai]

I recently acquired some Hell Creek Dromaeosaur teeth specimens and examined them just to study their features and get to know them more. Most of the teeth have the rather re-curved and compressed bladed shape with different size of serrations on the interior and anterior serrations until I ran into a few teeth that seem to have a fatter and more conical, with serration on only on the interior side but seem to have no serration on the anterior side. Upon closer examination with the loupe, It doesn't look like it's worn out or anything, just doesn't seem to be there.

Here is the Dromaeosaur tooth I am talking about:

I have read from somewhere I can't remember now that some Tyrannosaur teeth in certain mouth positions may not have serration such as the triangular-shaped teeth that are often marked as Aublysodon. Plus, when I compared the strange dromaeosaur tooth to one of my small Nanotyrannus tooth that I have (this one was I.D. by CK Preparation to be Nanotyrannus rather than Dromaeosaur) it seem to have a lot in similarity at least from as much as I can tell and assuming that the Nanotyrannus baby tooth I have is really Nanotyrannus.

Here is the presumed Nanotyrannus tooth that I have for comparison:

So I am wondering, if my dromaeosaur may have been a misidentified baby Tyrannosaur tooth, or there really are Dromaeosaur teeth that have serration on only on the interior side, and perhaps what I really thought is a baby Nanotyrannus tooth is really another off-shoot of the variety of Hell Creek Dromaeosaur teeth?

Any insight from Hell Creek theropod experts that could shine a light on my curiosity would be greatly appreciated. Thx

[Troodon]

AJ

Have you see this recent post? See if it helps on your dromaeosaur question.

http://www.thefossilforum.com/index.php?/topic/54726-how-to-identify-acheroraptor-teeth-from-the-hell-creek-formation/

To address your question on teeth having no serration. They are only seen on pre-maxillary teeth of tyrannosaurids and can either Nano or Rex. Your fat tooth has all of the characteristics of being a juvie T-rex.

Edit: Note when examining pre-maxillary teeth for the existence of serrations it must be done under a high power loop or scope. Serrations can been worn badly and many not be visible to the naked eye. I also believe that Aublysodon is no longer considered to be a valid species.

Edited May 24, 2015 by Troodon

[jpc]

As I understand it one of the characteristics of dromeosaurs (non premax teeth) is that the anterior serrations are smaller than the posterior serrations. (or is it the other way around?). So by default, anything with only one row of serrations is not a dromeosaur.