Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Gastropoda Cuvier, 1795 - snails and slugs
     Subclass Divasibranchia Minichev & Starobogatov, 1975
       Order Stylommatophora Schmidt, 1855 see Infraorder Stylommatophora Schmidt, 1855
         (Achatinid Sigmurethra)
           Suborder Sigmurethra Pilsbry, 1900 see Group Sigmurethra Pilsbry, 1900
             Superfamily Strophocheiloidea Pilsbry, 1902 see Superfamily Acavoidea Pilsbry, 1895
               Family Dorcasiidae Connolly, 1915
                 Genus Trigonephrus Pilsbry, 1905