living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Eukaryotae see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Subkingdom Eumetazoa Butschli, 1910 see [unranked] Eumetazoa Bütschli, 1910
         Phylum Mollusca Linnaeus, 1758 - molluscs
           Class Gastropoda Cuvier, 1795 - snails and slugs
             Subclass Prosobranchia Milne-Edwards, 1848 - prosobranchs see Class Gastropoda Cuvier, 1795
               Order Archaeogastropoda Thiele, 1925 see Order Vetigastropoda Salvini-Plawen, 1980
                 Superfamily Fissurellacea Fleming, 1822 see Superfamily Fissurelloidea Fleming, 1822
                   Family Fissurellidae Fleming, 1822 - keyhole limpets
                     Subfamily Fissurellinae Fleming, 1822
                       1 Genus Fissurella Bruguière, 1789
                       2 Genus Amblychilepas Pilsbry, 1890
                       3 Genus Cosmetalepas Iredale, 1924
                       4 Genus Fissurellidea d'Orbigny, 1841
                       5 Genus Lucapina Sowerby, 1835
                       6 Genus Lucapinella Pilsbry, 1890
                       7 Genus Macrochisma Gray, 1840, orth. inval. see Genus Macroschisma Sowerby, 1835
                       8 Genus Megatebennus Pilsbry, 1890