Bear Paw formation, Montana

Top and bottom views of brain endo-cast from the pterosaur Anhanguera (Witmer).

photo credit Mike Dvorak

Echinoid (starfish) “arm” split laterally, along with ammonite, brachiopod and pelecypod hash from Plesiosaur Hill.

Suture patterns from baculites cephalopods.

Partial ammonite, probably sp. Placenticeras, comprised of ammolite, an opal-like organic gemstone.