Unio sp. Fossil Bivalve - Judith River Formation

Description

Species: Unio sp.
Formation: Judith River Formation
Location: Hill County, Montana
Age: 79-75 mya, Cretaceous
This is an authentic fossil bivalve negative cast from the Judith River Formation of Montana. It is a fairly large specimen for this formation, most of the bivalves from the Judith are about the size of a grape. This specimen has no more of the original shell, what is left is the internal cast of the specimen showing the original shape of the inside of the shell. This is a nice piece for anyone collecting unusual shells or rarely seen Judith River material, as very few people seem to bother digging the invertebrate fauna of the formation.