This Specimen has been sold.
.42" Cretaceous Crocodilian Vertebra (Champsosaurus) - Montana
Here's a small tail vertebra from the Cretaceous aged reptile Champsosaurus sp. It was collected from private land from the Two Medicine Formation (Judith River Group) of Montana.
Champsosaurusis an extinct genus of diapsid reptile belonging to the order Choristodera. It grew to about 1.50 m (5 ft) long, though C. gigas, the largest species, reached 3-3.5 m (10–12 ft) in length. Champsosaurus resembled a gharial and, like gharials, hunted in rivers and swamps, catching fish with its long, tooth-lined jaws. It probably swam with lateral body movements, pinning its limbs against its body to increase its streamline, just like crocodiles and the Marine Iguana. Behind the eyes Champsosaurus's skull was very wide as powerful jaw muscles were attached here.