Help with Hell Creek ID

[clarevoiyant]

I recently bought this tooth from a sort of reputable seller that largely only deals in Hell Creek materials. I've been told that she sometimes do however get her Identification of materials wrong. This tooth here is labelled by her as Nanotyrannus but I had @Andy look at this and he said that I should seek better advice from the experts as he doesn't think it is a Nanotyrannus seeing that the tooth is a little too thick for Nano and a little too thin for T-rex. Attached are a few photos and I've also attached a microscopic zoomed in on the serrations. Serration count is 3 per mm.

[Runner64]

Look like a tyrannosaur tooth and by looking at the cross section I think it is Nanotyrannus and not T-Rex. I think this because the cross section is more of a rectangle shape and has straight lines. A Rex tooth would look more like an oval in the cross section and not a rectangle.

[Troodon]

What is the size of the tooth and where did you take the serration count and over what distance

[-Andy-]

I handled this tooth but couldn't come to a conclusion either.

 

I first thought it was a Judith River tyrannosaur but Clarence later clarified it's from Hell Creek. This surprised me as the thickness of the tooth feels right for JRF, but is too fat for Nano and too thin for Rex to me.

[clarevoiyant]

1 hour ago, Troodon said:

What is the size of the tooth and where did you take the serration count and over what distance

To clarify, I'm a complete newbie at identifying tooth (hence I'm here). I didn;t know to count it over 5 mm. I counted the serrations just over 1 mm. Hahas.

Tooth is 2.4 cm (straight) and 2.8 cm curved (long side)

[Runner64]

1 hour ago, clarevoiyant said:

To clarify, I'm a complete newbie at identifying tooth (hence I'm here). I didn;t know to count it over 5 mm. I counted the serrations just over 1 mm. Hahas.

Tooth is 2.4 cm (straight) and 2.8 cm curved (long side)

You might find this previous post by Troodon informative. It's a very helpful and a useful guide to identifying tyrannosaur teeth in the Hell Creek and Lance Formations.

 

[Susan from PA]

Judging by the cross-section, it does seem to me to be of rectangular shape.  Some T.rex maxillary teeth can be compressed as well.  I tend not to get into a serrations count with these smaller Tyrannosuar teeth from Hell Creek.  There are only 2 described, so, it's either Nano or T.rex.  To me, the tooth looks too compressed to confirm it being from a T.rex. If this were in my collection, I would call it Nanotyrannus.  

[Troodon]

One lesson for a newbie don't trust any identification given to you by anyone.  Reputable dealers can misdiagnose teeth so can collectors.  Educate yourself and become an expert and always question identifications since it's not an exact science and difficult for isolated teeth.  This tooth is not a slam dunk and I'm leaning toward Trex but I would like to hold it to be sure since pictures are not the best tool for seeing teeth.   Yes it's base is rectangular but with questionable teeth you have to look at all features not just one since maxillary rex teeth can be compressed at the base.  I'm leaning toward Rex for a several reasons, the serrates are classic rex chisel shaped, very robust serrations and the tooth does not appear to be compressed overall but more important the tip is very robust not Nano like..

 

 

Serration although not critical for identification of smaller teeth tyrannosaurid teeth fits the range I've seen on other Trex teeth.

[mattman10]

What Troodon said - the serrations and tip all point toward a small Rex tooth, rather than Nanotyrannus.  Although I'm sure the dealer felt more comfortable labelled it Nanotyrannus due to it being sleeker than the majority of rex teeth and quite small.

[Susan from PA]

14 hours ago, -Andy- said:

I handled this tooth but couldn't come to a conclusion either.

 

I first thought it was a Judith River tyrannosaur but Clarence later clarified it's from Hell Creek. This surprised me as the thickness of the tooth feels right for JRF, but is too fat for Nano and too thin for Rex to me.

My kids recently got some Tyrannosaurid teeth from the Judith River Formation.  I haven't held many of these teeth, as I started collecting mainly from Hell Creek, but look how compressed this one is.  

[-Andy-]

8 hours ago, Susan from PA said:

My kids recently got some Tyrannosaurid teeth from the Judith River Formation.  I haven't held many of these teeth, as I started collecting mainly from Hell Creek, but look how compressed this one is.  

 

 

Good one. If someone showed me this tooth with no data whatsoever, my first thought would've been Nanotyrannus from Hell Creek.

[Susan from PA]

8 hours ago, -Andy- said:

 

Good one. If someone showed me this tooth with no data whatsoever, my first thought would've been Nanotyrannus from Hell Creek.

Yes indeed!  Another example of why location is so important.