Class Bivalvia Linnaeus, 1758 - bivalves Subclass Autobranchia Grobben, 1894 1 Family †Cercomyidae Crickmay, 1936 2 ?Family †Palaeocardiidae Scarlato & Starobogatov, 1979 3 Family †Pucamyidae Sánchez, 2007 4 Superorder †Nepiomorphia Kříž, 2007 5 Superorder Pteriomorphia Beurlen, 1944 6 Superorder Heteroconchia Gray, 1854