Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Bivalvia Linnaeus, 1758 - bivalves
     Subclass Pteriomorphia Beurlen, 1944 see Superorder Pteriomorphia Beurlen, 1944
       Order Ostreida Férussac, 1822
         Suborder Ostreina Férussac, 1822 see Order Ostreida Férussac, 1822
           Superfamily Ostreoidea Rafinesque, 1815
             Family Gryphaeidae Vialov, 1936
               Subfamily Pycnodonteinae Stenzel, 1959
                 Tribe Hyotissini Scarlato & Starobogatov, 1979
                   Genus Parahyotissa Harry, 1985
                     1 Subgenus Pliohyatissa Vaught, 1989, orth. inval. see Subgenus Pliohyotissa Harry, 1985
                     2 Subgenus Numismoida Harry, 1985