A bivalve mollusc is a type of aquatic animal that has two shells connected by a HINGE. Examples of bivalve molluscs include scallops, clams, and cockles. Scallops have a fan-shaped shell with radiating ribs, while clams have two equal-sized shells that are hinged together. Cockles have a heart-shaped shell and are usually found in sandy areas. All of these bivalve molluscs are characterized by their two shells connected by a HINGE.