Class Bivalvia Linnaeus, 1758 - bivalves Subclass Protobranchia Pelseneer, 1889 Order Nuculida Dall, 1889 [monotypic] Superfamily Nuculoidea Gray, 1824 Family Sareptidae Stoliczka, 1870 1 Subfamily Sareptinae Stoliczka, 1870 2 Subfamily Pristiglominae Sanders & Allen, 1973