A NEW UNIONOIDEA (MOLLUSCA, BIVALVIA) FROM THE TACUAREMBO FORMATION (UPPER TRIASSIC-UPPER JURASSIC),

A new genus and species of Unionoidea, Tacuaremboia caorsii, are described from the Tacuaremb6 Formation (Upper Triassic-Upper Jurassic) of Uruguay. The genus is distinguished from other Unionoidea by its large size, thickness, edentulous hingeline, and the presence of claustra. It has some similarities with the Anodontinae and the Archanodontacea, but it cannot be assigned to any of the known family units.