White River carnivore jaw section - Hyaenodon? Nimravid?

[Opabinia Blues]

I found this front bit of carnivore jaw while out on my latest fossil collecting trip in the White River Formation of Colorado. Only one tooth is complete, the canine tooth has broken off. It’s too large to be Hesperocyon and the cross section of the canine tooth does not match that of Daphoenus, which I have previously collected material, including a canine tooth, from. That leaves Hyaenodon and the Nimravids. 

 

After doing some comparative research with pictures of skulls, I am tentatively leaning towards this being from a Nimravid, as the contours of the jaw line near the socket where the canine tooth sits are fairly distinctive and match those in the pictures of Nimravid skulls almost perfectly, less so than the contours seen in the skull of Hyaenodon horridus. Plus, the canine tooth is triangular in cross section, and though I couldn’t find any specific references on this bit of anatomy that makes more sense to me for the stabbing canines of a Nimravid rather than the flatter canines of Hyaenodon. 

 

But alas, here I am to get other opinions. Hyaenodon or Nimravid? Or something else entirely? (I am fairly confident this isn’t just a piece of oreodont jaw, haha). 

 

Thanks in advance.

 

 

[PaleoNoel]

Quincy, I remember I suggested this was carnivore based on the top pics, however after looking at the chewing surface I think it has more in common with an oreodont maxilla. Hate to be the bearer of bad news. Since that tooth is broken on my own skull, I found one being sold online to compare it to. The triangular cross section of what remains of the canine is also consistent with oreodont.

Edited June 18, 2021 by PaleoNoel

[Opabinia Blues]

16 minutes ago, PaleoNoel said:

Quincy, I remember I suggested this was carnivore based on the top pics, however after looking at the chewing surface I think it has more in common with an oreodont maxilla. Hate to be the bearer of bad news. Since that tooth is broken on my own skull, I found one being sold online to compare it to. The triangular cross section of what remains of the canine is also consistent with oreodont.

 

 

That was my very first instinct when I found the thing in the field. I wasn’t fully aware of the shape of oreodont premolars, but it does have that triangular shape too doesn’t it. That’s what made me think carnivore when I looked at it again. I agree with this assessment.