Class Bivalvia Linnaeus, 1758 - bivalves
   Subclass Autobranchia Grobben, 1894
     Superorder Heteroconchia Gray, 1854
       Clade Palaeoheterodonta Newell, 1965
         Order Trigoniida Dall, 1889
           Superfamily †Megatrigonioidea van Hoepen, 1929
             1 Family †Megatrigoniidae van Hoepen, 1929
             2 Family †Iotrigoniidae Saveliev, 1958
             3 Family †Rutitrigoniidae van Hoepen, 1929