1.8" Fossil Baculites Section - Montana

This is a fossil Baculites section from the Pierre Shale of Montana.

Baculites ("walking stick rock") is an extinct cephalopod genus with a nearly straight shell. The matrix it is preserved in has been sculpted so that it stands up freely, making for a very aesthetic display. It's approximately 75 million years old, and comes from a time when a shallow sea covered much of South Dakota.