Tyrannosaur jaw?

[patrickhudson]

Judith river formation of Montana find.  My guess was a small tyrannosaur indet - maybe the anterior mandible??  Inside has the foramina and ridge seems to have worn tooth sockets.  Any help would be awesome.  I’ve never found anything like this so I don’t know if it’s more rare for the JRF or not.  Wish there was a tooth attached still 😉 

 

Edited November 22, 2024 by patrickhudson

[Carl]

I'm seeing nothing to suggest a jaw fragment. What makes you suppose tyrannosaur? I agree that it looks like fossil bone, and based on where it was found, it's likely a dinosaur. but it would be hard to take the ID past that point, in my opinion.

[patrickhudson]

4 minutes ago, Carl said:

I'm seeing nothing to suggest a jaw fragment. What makes you suppose tyrannosaur? I agree that it looks like fossil bone, and based on where it was found, it's likely a dinosaur. but it would be hard to take the ID past that point, in my opinion.

The smooth outside with foramina on the upper side, lingual foramina exactly where they should be in a jaw - several, as well as sockets for the teeth.  Tyrannosaur because everything else in that area is super obvious when you are talking jaw bone - triceratops and edmontosaurus.

[patrickhudson]

My only other guess would be a very weird shaped epioccipital frill piece 

[jikohr]

The blood groves are making me think Ceratopsian. Though I would love nothing more than to be wrong and for that to be Tyrannosaur.

[patrickhudson]

6 minutes ago, jikohr said:

The blood groves are making me think Ceratopsian. Though I would love nothing more than to be wrong and for that to be Tyrannosaur.

Tough to argue against that - the more I think about it.  Don’t think tyrannosaur jaws have blood grooves like that.  

[jpc]

The texture is all wrong for a tyrannosaur.  I see bone fibers going in all direction in the last photo in your original post which, as far as I know, is only found on ceratopsian frills and ankylosaur osteoderms.  

[Carl]

On 11/22/2024 at 8:41 AM, patrickhudson said:

The smooth outside with foramina on the upper side, lingual foramina exactly where they should be in a jaw - several, as well as sockets for the teeth.  Tyrannosaur because everything else in that area is super obvious when you are talking jaw bone - triceratops and edmontosaurus.

Sorry, I'm not seeing anything that could be called a socket.

Edited November 26, 2024 by Carl