Class Bivalvia Linnaeus, 1758 - bivalves Subclass Autobranchia Grobben, 1894 Superorder Pteriomorphia Beurlen, 1944 Order Arcida Gray, 1854 Superfamily Arcoidea Lamarck, 1809 Family †Parallelodontidae Dall, 1898 1 Subfamily †Parallelodontinae Dall, 1898 2 Subfamily †Grammatodontinae Stephenson, 1941