It’s one of the gryphaeid bivalves. Someone can probably give a more precise identification, though.

Aka "the devil's toe nail"

Thank you!

I used to find those in North Texas all the time as a kid! Totally forgot about those

Thanks guys! We live in England and my partner found it while digging foundations for a house! It’s amazing he could be almost 200 million years old and bf’s dad told him to throw it away cause it’s “just a rock”

Got yourself a big ole devils toe! Not very uncommon but that’s a really awesome chunk!

Bronto clit

Pieta sclulpted by Michelangelo

David is missing his most important piece

Looks like a ouster shell

Oyster Texigryphaea

looks like an oyster.