Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Gastropoda Cuvier, 1795 - snails and slugs
     Subclass Prosobranchia Milne-Edwards, 1848 - prosobranchs see Class Gastropoda Cuvier, 1795
       Superorder Archaeogastropoda Thiele, 1925
         Order Vetigastropoda Salvini-Plawen, 1980 - archaeogastropods s.l.
           Superfamily Fissurelloidea Fleming, 1822 [monotypic]
             Family Fissurellidae Fleming, 1822 - keyhole limpets
               Subfamily Fissurellinae Fleming, 1822
                 Genus Atractotrema Cossmann, 1888