Ischyromys? (rodentia)

[Peat Burns]

I am looking for confirmation of the identity of this rodent jaw from the White River Group of NW Nebraska.  I am thinking Ischyromys.  Thoughts?

 

Scale is mm.  Occlusal view enlarged and not to scale.

 

@jpc, @Fruitbat, @Nimravis 

 

[Tidgy's Dad]

Again, can't help, but it's a stunning piece. 

[Auspex]

Pretty distinctive enamel pattern; from what I can find on-line for comparison, I think you have the right of it.

Nice squirrel!

[jpc]

 It is certainly a rodent, and a fairly robust lower jaw, so Isch is a good guess.  We have an Ischyromys specimen at work.... I can compare it on Monday.

[doushantuo]

 

Awesome find and well photographed,kudos!

Heaton on the genus(1996 OR 2005 ,not sure):

 

Can recommend the following for its scope,dentition not overly figured

 

 

 

 

 

 

[jpc]

doushantuo... your posting of actual scientific papers is incredible.  Do you find these online or do you have an incredible personal library? 

[doushantuo]

Others post better stuff:Troodon,HarryPristis,Abyssunder,Piranha,Fruitbat.

 

[Peat Burns]

5 hours ago, Tidgy's Dad said:

Again, can't help, but it's a stunning piece. 

Thanks, Adam 

4 hours ago, Auspex said:

Pretty distinctive enamel pattern; from what I can find on-line for comparison, I think you have the right of it.

Nice squirrel!

Thanks, Auspex.  I found it this summer, and I had rough-sorted the jaw fragments in the field and had it in with the cf. Leptomeryx.  Then last night I started working on IDs and saw those beautiful teeth under the scope and realized I had a new species (new to me).

1 hour ago, jpc said:

 It is certainly a rodent, and a fairly robust lower jaw, so Isch is a good guess.  We have an Ischyromys specimen at work.... I can compare it on Monday.

Thank you, jpc.

 

@doushantuo , thanks very much for those papers.  Very helpful as usual.  

[doushantuo]

An Answer to JPC,march 31,2018:

I have a pretty useful paper AND digital library at home ,but alas,no database to speak of.

edit.: my memory for (micro)mammal literature is pretty eidetic ,and a conservative estimation of having read several hundreds of articles,all from top peer-reviewed

journals,  seems reasonable

 

Edited June 23, 2022 by doushantuo

[ParkerPaleo]

Can confirm Ischyromys

 

Comparison material from my collection.

 

 

Totally need a better camera setup....

Edited June 23, 2022 by ParkerPaleo