Phylum Mollusca Linnaeus, 1758 - molluscs
   Conchifera Gegenbaur, 1878 see Subphylum Conchifera Gegenbauer, 1878
     Class Scaphopoda Bronn, 1862 - tusk shells
       Order Gadilida Starobogatov, 1974
         Suborder Gadilimorpha Steiner, 1992
           Family Gadilidae Stoliczka, 1868
             Subfamily Siphonodentaliinae Tryon, 1884
               1 Genus Dischides Jeffreys, 1867
               2 Genus Polyschides Pilsbry & Sharp, 1898
               3 Genus Sagamicadulus Sakurai & Shimazu, 1963
               4 Genus Siphonodentalium Sars, 1859
               5 Genus Striocadulus Emerson, 1962