Class Bivalvia Linnaeus, 1758 - bivalves Subclass Autobranchia Grobben, 1894 Superorder Pteriomorphia Beurlen, 1944 Order Mytilida Férussac, 1822 Superfamily †Modiolopsoidea Fischer, 1886 Family †Saffordiidae Scarlato & Starobogatov, 1979