Gastropod?

[WallaceGavin]

I can’t identify exactly what these are? Found them in Barton Creek near Austin. They look like a gastropod but haven’t seen any with the rears this out to the edge. Also the other pointy ones are even about the center while this one is near the back end. 

[Lone Hunter]

I know them as Rams horn oysters.

[Fossildude19]

I believe these are actually oysters.

One of the locals will chime in with a genus soon.

@JohnJ  @erose

[WallaceGavin]

1 hour ago, Lone Hunter said:

I know them as Rams horn oysters.

Yep that appears to be it! 

[FossilDAWG]

 IIymatogyra, I believe.  Perhaps  IIymatogyra arietina.

 

Don

[JohnJ]

1 hour ago, FossilDAWG said:

 IIymatogyra, I believe.  Perhaps  IIymatogyra arietina.

 

Don

Indeed.

[erose]

Yep, FossilDAWG has it correct.