Weird Hollow Miocene? Bone - Calvert Cliffs

[HemiHunter]

One of my boys collected this strange joint bone fragment while we were at Calvert Cliffs yesterday.  It has a shape we can't figure out--and it's completely hollow! It's too big to be bird (right)? So is there a natural process that could have hollowed it out like this? And what is it? Can anybody help?

 

[HemiHunter]

[HemiHunter]

[HemiHunter]

[HemiHunter]

[bthemoose]

No ideas from me, but that’s a really interesting find! 

[FossilsAnonymous]

@sharkdoctor

[Rockwood]

3 hours ago, HemiHunter said:

So is there a natural process that could have hollowed it out like this? And what is it?

Erosion.

[LabRatKing]

I’ve seen this happen in modern and historical bones. The spongiform tissue collapses or is eaten away by rodents leaving only the outer, dense bone layers. You may be able to see gnaw  marks if you look hard, but this is likely a result of natural erosion.

 

No clue as to what this is from, but looks like remnant of a femur or humerus.

[Rockwood]

3 hours ago, HemiHunter said:

It has a shape we can't figure out--and it's completely hollow!

I'm thinking modern cow is high on the possibilities list. Are you sure it's a fossil ? 

[LabRatKing]

5 minutes ago, Rockwood said:

I'm thinking modern cow is high on the possibilities list. Are you sure it's a fossil ? 

I agree, a burn test might be a good idea.

[LordTrilobite]

I'm thinking that's a very eroded mammal humerus fragment.

[HemiHunter]

3 hours ago, LabRatKing said:

I agree, a burn test might be a good idea

So, it is not particularly smelly in the burn test, but it also does not feel as dense or sound as "pingy" as our many other mineralized fossil bones. We compared it to a (larger) modern moose femur fragment I just happen to have lying around. The shape is similar and the "feel" compares well. (Don't know why I didn't think to do that in the first place).  Based on the above, I'm going with an old, but modern cow femur. Great to learn some more about fossil bone ID.  Thanks!!

 

[Rockwood]

1 hour ago, HemiHunter said:

modern moose femur fragment I just happen to have lying around.

Anyone who just happens to have a moose bone is all right in my book.