Fish Skull Fragment?

[Cowboy Paleontologist]

I found this fragment in a Cretaceous conglomerate.  I am still trying to figure out the name of the formation, but it is either from a river bottom or sea shore.  My first thought when I found it was a piece of turtle shell, but upon closer examination, it reminds me more of fish skull fragments I have found in other formations.  I was hoping some of you might be able to provide some other perspectives.  The piece is ~12 mm long, ~10 mm wide, and ~2 mm thick.  It is slightly convex with a slight bumpy texture on the outside, although mostly eroded away, and some sutures at the very edge on the inside.

[MeargleSchmeargl]

Not my area of expertise. Doesn't look like much to me, but what do I know?

[Al Dente]

It looks like part of an echinoid. The last photo shows an ambulacrum.

[LordTrilobite]

Could be cartilage.

[Cowboy Paleontologist]

51 minutes ago, MeargleSchmeargl said:

Not my area of expertise. Doesn't look like much to me, but what do I know?

You're correct in that it isn't much   

But it is a little bit of something, so that is why I'm here.  As far as I know, very little is known about this area except that copious quantities of Gryphaea oysters can be found.

 

 

56 minutes ago, Al Dente said:

It looks like part of an echinoid. The last photo shows an ambulacrum.

Comparing this to pictures I found on the interwebs, what I thought was bone sutures does resemble ambulacra more than fish skull fragments or turtle shells from my collection.