11-02-19 lake macconaughy bone

[Micah]

Hi I found this on the beach at lake mcconaughy in Nebraska which means it could be Pleistocene or Miocene but most likely from the Ash Hollow formation. I’m pretty clueless when it comes to bones and could use some help figuring out what this is. Thanks! P.s. I did the flame test and it’s fully mineralized.

[Shellseeker]

Why am I thinking sea turtle humerus?  It would be one possibility.

[Micah]

1 hour ago, Shellseeker said:

Why am I thinking sea turtle humerus?  It would be one possibility.

I don’t think so because Nebraska was completely land locked at the time of these deposits. Turtle maybe; but def not from the sea.

[Micah]

@Harry Pristis Any ideas? lol sorry I keep tagging you in things, you seem to be one of the most knowledgeable about American Pleistocene and Miocene fossils on the forum... 

[Harry Pristis]

Sorry, Micah, I don't have an ID for you.  I do, like Shellseeker, get a sense of turtle or tortoise limb.

[jpc]

I am seeing a mammal calcaneum.  

 

(No sea turtles in Nebraska; certainly not near Lake McC.).  

[Micah]

Thanks guys, is there anything in particular that points to it being reptilian as opposed to mammalian or is it just experience?

[Shellseeker]

2 minutes ago, Micah said:

Thanks guys, is there anything in particular that points to it being reptilian as opposed to mammalian or is it just experience?

For me, mostly on the shape. I have seen both land tortoise and sea turtle bones that are generally shaped like this one.

I am not familiar with the texture and fossilization processes in Nebraska that are in play.

As  JPC indicates, another bone that resembles yours is calcaneum. You might search TFF to see how close that bone seems to yours...

[Micah]

1 hour ago, jpc said:

I am seeing a mammal calcaneum.  

 

(No sea turtles in Nebraska; certainly not near Lake McC.).  

I’ve looked at calcaneum from a lot of animals posted on the forum and am not seeing the resemblance...

[Micah]

After a bit of digging through resources I’m definitely leaning towards reptile humerus and probably tortoise based on time and location. I haven’t been able to find a good resource for identifying species in the ash hollow formation, so if anyone knows of one I’d be grateful. Side note, I’m pretty excited now, because aside from turtle shell fragments this is my first reptile bone find!

[jpc]

This has a concave articular surface on the side of the bone.  There are very few bones that have that.  Mammalian ulna and calcaneum are the two examples I can think of.  I just don't see a turtle leg bone in there.   

[Micah]

Lol I’m at your mercy guys... I simply lack the experience/knowledge on this front. So far nothing I’ve compared it to matches. The mammal ulnas and calcaneus I’ve looks at look nothing like this, maybe I’m looking at the wrong animals, but turtle humerus is still closest. I’m willing to be convinced, but haven’t found good evidence.

[Ash]

Have you tried emailing any museums nearby?

[Micah]

Haven’t yet, thought I’d try here first. Lol I’ll be emailing someone at morrill hall soon though unless I’m convinced of anything in particular soon.