Class Bivalvia Linnaeus, 1758 - bivalves Subclass Autobranchia Grobben, 1894 Superorder Heteroconchia Gray, 1854 Clade Palaeoheterodonta Newell, 1965 Order Trigoniida Dall, 1889 Superfamily Trigonioidea Lamarck, 1819 Family Trigoniidae Lamarck, 1819 Subfamily Trigoniinae Lamarck, 1819