Pelecypod, Mollusk, Utah F934 - Pelecypod, Mollusk, Utah. This Pelecypod fossil is from Utah, an area that once was covered by shallow seas. Cretaceous age - 100 million years old. Unlike the bivalves, where the mollusks had two sections of shell hinged together, this ancient snail-like mollusk had only a top shell section and the animal filled the underside of the shell with its body exposed underneath. From Utah. GREAT PRICE Price: $6.50  (You can always remove items from your cart later if you wish)