yet another Nanotyrannus tooth ... or?

[JoeS]

Hi all, I could not resist and took another shot on my quest to obtain a Dakotaraptor tooth.
Here the tooth in question this time:
It was found in the Hell Creek Formation, Garfield County.
Measurements are: CH 1,41 cm - CBL 0,68 cm - CBW 0,3 cm - denticles per 5mm are 22 mesial and 19 distal.
Note the slight tilt of the denticles towards the tip of the tooth.
It's the best fit I have found so far, what deviates from the dePalma description is the shape of the base, it has a pinch, but I would not consider it rectangular. As a side note, it looks exactly like the base of Acheroraptor teeth I have in my collection.
But, I am not an expert

Thanks for taking a look!

[Troodon]

We have multiple issues with identifying these teeth.   First the paper that described them included a turtle bone that was thought to be Dakotaraptor and most believe one of the limb bones looks identical to Anzu so do we have a clear understanding about this dinosaur?  Did the isolated teeth found at the dig site belong to this animal?  Do the teeth change in the jaw?  All we have are images of 2  and ranges of its size no side or base profile.  In speaking with W. Stein he says the base is someone Almond shaped not fig 8 shaped like your images, but I really cannot verify that.   To make matter worst, as you know, these teeth closely resemble juvie Nanotyrannus as well as DSDI figures.

 

Having said all of this I believe your new specimen is yet another Nanotyrannus.   I say that for a couple of reasons

The holotype's Crown Height Ratio (CHR) range 1.9 to 1.6 and yours is 2.07

 

 The second is the denticles.  Yours look very much like Tyrannosaurid square and chisel shaped.  Compare them to the holotype tooth..

 

 

 

 

 

 

 

[JoeS]

thanks @Troodon   Yeah, I really do think that we need either another Dakotaraptor or a Nanotyrannus paper for that manner with clear and crisp images and overall more data-points. These size ranges given for Dakotaraptor based off of four teeth are only somewhat useful.
Any chance that Walter Stein would make some more pictures publicly available? I went through his online Research Collection Database without success.

One thing that is peculiar to me is the range of denticle shapes that are assigned to Nanotyrannus, I guess some might be due to juvenile to adult variations, but still. Again, a paper on that matter would be great.

[Troodon]

Unlikely to get the detail we need and since many believe Nanotyrannus is a Trex we are also unlikely to see those teeth published.   What we really need is a DR jaw with some teeth that can be published and analyzed.  Currently we just have isolated teeth and I have a hard time supporting any assignments unless the tooth is fully documented.  I usually see Walter in Belle Fouche when I go digging.  Hopfully that happens in June and I'll try to get my hands on some..   

I see that range of denticles on all Tyrannosaurid teeth.  A study I did on 30 Nano teeth showed Distal density ranging from 2.2 to 3.6/mm on teeth around 1".  On Trex teeth around 1" I saw a range of 2.6 to 3.5/mm.  So lots of variations 

[JoeS]

40 minutes ago, Troodon said:

I'll try to get my hands on some..   

That would be great!

[Troodon]

I did get a chance to see one Dakotaraptor tooth he had in Belle Fouche and took a couple of photos of base and serrations.  The rest of his collection is back home in Florida.   

 

Updated my topic on DR

 

 

[JoeS]

6 minutes ago, Troodon said:

I did get a chance to see one Dakotaraptor tooth he had in Belle Fouche and took a couple of photos of base and serrations.

Thanks so much for looking into this and providing images! That base is indeed very unique. I'll continue on my quest to obtain one of those rare beauties