Hoploscaphites Ammonite Resting On Baculites

This is a really cool piece from the Pierre Shale of South Dakota. There is a Hoploscaphities brevis ammonite resting on top of a section of a large Baculites (straight cephalopod) There is also a section of a second, small Baculites right next to it. The ammonite is about 1.8" wide and the entire piece is 4.4" tall. The preservation is wonderful, with iridescent shell and lots of sutures showing on the Baculites.

These 70 million year old ammonites lived when South Dakota was a shallow inland sea. It was found preserved in a concretion that was split open. It then had to be hand prepared to remove the hard rock surrounding it from the shell, a very time consuming task.