Ceratopsian frill?

[patrickhudson]

I posted this a while ago, but I’ve cleaned it up and taken a different angle of the agatized inside.
 

Montana milk river Judith formation.  It seems to have the vessel grooves on one side, but is obviously very worn.  Agatized heavily only the inside but even visible from the outside.   
the agatized portion looks super similar to another bone found in the area (fourth pic).  I don’t know how the agate process works, but the one the fourth picture that sure seems like a bone has the same agate characteristics as the “frill” 

-or... maybe it’s a rock

 

again- fourth picture is a different “bone” just to show the agatization 

[Captcrunch227]

I’ll be watching this one. Some pictures on this seems like it might be bone but it has a wood appearance to me for some reason.
 

Just so hard to tell in these photos. You have to upload small files so a good quality picture is hard to get on this forum. I vote bone but I wouldn't bet a single red cent on my guess being right 

[Troodon]

Does not jump out to be one, might be but blood vessels are not very defined.  Might just be the poor preservation