Class Bivalvia Linnaeus, 1758 - bivalves
   Subclass Autobranchia Grobben, 1894
     Superorder Heteroconchia Gray, 1854
       Clade Palaeoheterodonta Newell, 1965
         Order Unionida Gray, 1854
           Superfamily †Trigonioidoidea Cox, 1952
             Family †Trigonioididae Cox, 1952
               1 Subfamily †Trigonioidinae Cox, 1952
               2 Subfamily †Americunioninae Guo, 1986
               3 Subfamily †Danlengiconchinae Sha, 1993
               4 Subfamily †Martinsonellinae Sha, 1993
               5 Subfamily †Peregrinoconchinae Gu, Chen & Lan, 1976