This Specimen has been sold.
Hoploscaphites Ammonite With Clam Fossils - Montana
This is a specimen of the ammonite Hoploscaphites crassus from the the Pierre Shale of Montana. It's just under 3 inches wide. There is a partial ammonite and several plan fossils found in the same concretion attached to it. The ammonite is slightly crushed by still retails some of it's iridescent shell preservation.