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 Mesogastropoda Thiele, 1925 - mesogastropods see [unranked] mesogastropods
                 Superfamily Calyptraeacea Lamarck, 1809, nom. illeg. see Superfamily Calyptraeoidea Lamarck, 1809
                   Family Calyptraeidae Lamarck, 1809 - slipper snails and shelf limpets
                     1 Genus Calyptraea Lamarck, 1799
                     2 Genus Crucibulum Schumacher, 1817
                     3 Genus Crepidula Lamarck, 1799