Is this a worn dinosaur ungual?

[Opabinia Blues]

This is probably a long shot but I figure I’d post it anyway because I’m really not sure what bone this chunk could be from…

 

This is a large chunk of bone (over 15 cm in diameter) from the Hell Creek Formation with a unique shape. A personal find. It’s rounded on one end but tapers at the other, however at the tapering end it’s fairly obviously broken whereas the rounded end appears to simply be weathered. One side is convex like a dome whereas the other side is concave like a bowl. The entire piece is heavily weathered, although there is some intact cortical bone in the concave side. 

Convex side:

Concave side:

 

Thickness:

 

I’ve only ever seen pictures of herbivore unguals, so I’m not sure how well this piece actually matches their shape. If it is an ungual my guess would be Edmontosaurus.

 

Can anyone confirm or deny? And, if not an ungual, any guesses as to what bone or taxon this could be from, or should I leave it in the “chunk-o-saurus” bin? Much thanks.

[jpc]

troodon may have a more detailed opinion, but I would call this a big ole chunkosaur. 

[Troodon]

Agree, I don't see it

Here is an Edmontosaurus ungual you can compare agsinst.  Its pretty thin with lots of small holes throughout the face