Post oak creek Texas

[Tx4life972]

After looking around at spots in dfw I had decided to check out post oak river on the west side of the service road I climbed down the embankment where I found a lot of shells like this one pictured no idea what exactly it is I’m very new to this and looking for info. I thought it might be a devils toe nail. 

 

[DPS Ammonite]

It is an oyster: Cameleolopha bellaplicata.  

 

[Tx4life972]

Thank you DPS Ammonite I’m planning on getting a sifter to see if I can get some shark teeth from there as well.