White Iridescent, 5" Baculites Section - South Dakota

This is a 6.6" long section of a large Baculites fossil from the Pierre Shale of South Dakota. It has a white opalescent shell with beautiful hues of purple and green.

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.