fossil I.D.

[RoG1]

Found this fossil in central Texas (Glen Rose formation), but it was found in rock that was hauled in around my sister's house.  So I don't know if it's Cretaceous or not (sure looks like central Tx limestone, tho).

 

[Ludwigia]

Looks like a bivalve impression showing the hinge. Some kind of oyster I would estimate.

[JohnJ]

Possibly Trigonia.

[RoG1]

So this is an impression of the outside of the open shell? - it's hard to see the orientation.....

 

Thanks for the responses.

[Ludwigia]

3 hours ago, RoG1 said:

So this is an impression of the outside of the open shell? - it's hard to see the orientation.....

 

Thanks for the responses.

It's an partial impression of the insides of two wide open valves with the hinge smack dab in the middle of it. John could very well be right with Trigonia.