White River Carnivoran Jaw Section

[PaleoNoel]

Hello again. I wanted to share this jaw section I found in Wyoming's White River back in July 2020. My initial thoughts were that it belonged to the primitive canid Hesperocyon, which in my experience has been the most abundant carnivore in those badlands, however, it doesn't quite match the other material I found which I'm confident is dog. While scrolling through the forum I saw some similarities to a jaw section labelled as Daphoenus by @Nimravis on the thread below:

The fossil itself is 3 cm long and ~2 cm from the tip of the tooth to the base of the jaw. I'd be interested to see some opinions. 

@jpc @ParkerPaleo @siteseer

Edited July 13, 2022 by PaleoNoel

[siteseer]

Your jaw section seems deeper than a Hesperocyon would be.  I don't have a specimen with that tooth position present to compare it to but I think it is Daphoenus.  It's not a nimravid nor Hyaenodon.

 

@fossillarry should take a look too.

[PaleoNoel]

9 hours ago, siteseer said:

Your jaw section seems deeper than a Hesperocyon would be.  I don't have a specimen with that tooth position present to compare it to but I think it is Daphoenus.  It's not a nimravid nor Hyaenodon.

 

@fossillarry should take a look too.

Thanks for your input!

[PaleoNoel]

@Nimravis any thoughts?

[Nimravis]

11 hours ago, PaleoNoel said:

@Nimravis any thoughts?

No- other than carnivore. I will take a look at home and see if I have anything similar.

[ParkerPaleo]

I'm getting the Daphoenus vibe as well.

 

From Scott and Jepsen Monograph.

 

Plate 10 - Daphoenus vetus

Plate 12 - Daphoenus hartshornianus

 

 

It doesn't quite look like my canid material but I didn't have a great view of one.  But if you can find a Mesocyon to compare it against that would be good.

 

Edit:  Check here for Mesocyon.  https://www.researchgate.net/publication/267156681_Phylogenetic_systematics_of_the_Hesperocyoninae_Carnivora_Canidae   page 55.

Edited July 14, 2022 by ParkerPaleo

[fossillarry]

I examined the jaw Granite State Fossil Dude posted  and agree with him and siteseer that the specimen is not Hesperocyon gregarius. I have several jaw fragments like this specimen, my friend David Jones took them many years ago to to the University of Nebraska at Lincoln and showed to Dr Robert Hunt a fossil carnivore expert who Id them as one of two larger species of Hesperocyon such as H. coloradensis. So your specimen could still be Hesperocyon. How ever, more recently, Dr. X. Wang of the Los Angeles County Museum also a carnivore expert  considers Hesperocuon to be paraphyletic (not all members assigned to a genus belong to that genus) including both species of larger Hesperocyon are  included in this genus. So at the moment  this jaw will either be  reassigned to an existing genus or put into a new genus. So you have a great specimen either way. This fossil is much to small to be Daphoenous which is a member of the Amphicyonide.

[ParkerPaleo]

It compares favorably to this specimen of mine.  Which I had labeled 'Mesocyon' and is from the Sharps formation in Pennington county, SD.

 

But I do not have the occlusal views prepared on it.  Its sometimes difficult to compare line drawings to photos.  Sometimes you do really need to hold specimen in your hands.  His specimen and mine are both much larger than a standard Hesperocyon.  I do have small Amphicyonidae as well so I don't think its out of the size range there.  If you read Wang's publication in my previous post, you will find that even the researchers conflate "Mesocyon" and Daphoenus.  They are not well known.

 

[PaleoNoel]

On 7/14/2022 at 1:16 PM, ParkerPaleo said:

It compares favorably to this specimen of mine.  Which I had labeled 'Mesocyon' and is from the Sharps formation in Pennington county, SD.

 

But I do not have the occlusal views prepared on it.  Its sometimes difficult to compare line drawings to photos.  Sometimes you do really need to hold specimen in your hands.  His specimen and mine are both much larger than a standard Hesperocyon.  I do have small Amphicyonidae as well so I don't think its out of the size range there.  If you read Wang's publication in my previous post, you will find that even the researchers conflate "Mesocyon" and Daphoenus.  They are not well known.

 

 

On 7/14/2022 at 11:27 AM, ParkerPaleo said:

I'm getting the Daphoenus vibe as well.

From Scott and Jepsen Monograph.

Plate 10 - Daphoenus vetus

Plate 12 - Daphoenus hartshornianus

It doesn't quite look like my canid material but I didn't have a great view of one.  But if you can find a Mesocyon to compare it against that would be good.

Edit:  Check here for Mesocyon.  https://www.researchgate.net/publication/267156681_Phylogenetic_systematics_of_the_Hesperocyoninae_Carnivora_Canidae   page 55.

 

On 7/14/2022 at 12:09 PM, fossillarry said:

I examined the jaw Granite State Fossil Dude posted  and agree with him and siteseer that the specimen is not Hesperocyon gregarius. I have several jaw fragments like this specimen, my friend David Jones took them many years ago to to the University of Nebraska at Lincoln and showed to Dr Robert Hunt a fossil carnivore expert who Id them as one of two larger species of Hesperocyon such as H. coloradensis. So your specimen could still be Hesperocyon. How ever, more recently, Dr. X. Wang of the Los Angeles County Museum also a carnivore expert  considers Hesperocuon to be paraphyletic (not all members assigned to a genus belong to that genus) including both species of larger Hesperocyon are  included in this genus. So at the moment  this jaw will either be  reassigned to an existing genus or put into a new genus. So you have a great specimen either way. This fossil is much to small to be Daphoenous which is a member of the Amphicyonide.

 

On 7/14/2022 at 1:16 PM, ParkerPaleo said:

It compares favorably to this specimen of mine.  Which I had labeled 'Mesocyon' and is from the Sharps formation in Pennington county, SD.

 

But I do not have the occlusal views prepared on it.  Its sometimes difficult to compare line drawings to photos.  Sometimes you do really need to hold specimen in your hands.  His specimen and mine are both much larger than a standard Hesperocyon.  I do have small Amphicyonidae as well so I don't think its out of the size range there.  If you read Wang's publication in my previous post, you will find that even the researchers conflate "Mesocyon" and Daphoenus.  They are not well known.

 

 

Thank you both for your input! Either way I'm happy with it, even if it's a mystery caniform for the time being.

@MarcoSr @jpc Do you have any thoughts? 

[MarcoSr]

2 hours ago, PaleoNoel said:

 

 

 

 

Thank you both for your input! Either way I'm happy with it, even if it's a mystery caniform for the time being.

@MarcoSr @jpc Do you have any thoughts? 

 

Sorry, I can't add anything beyond carnivore.  The vast majority of the White River specimens that I've collected came from ant hills.  Unfortunately, the harvester ants can't carry around partial jaws the size of your jaw.  I do find isolated small carnivore teeth, but I really haven't tried to ID them.  My sons have found an incredible number of skulls and jaws from the larger White River carnivores, but I really haven't tried to study them.  Someone here on TFF posted the below picture in another thread (I can't remember who) that might help you.

 

 

 

 

Marco Sr.