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 Tonnacea Suter, 1913 see Superfamily Tonnoidea Suter, 1913 (1825)
                   Family Cassidae P.A. Latreille, 1825 - helmet snails see Subfamily Cassinae Latreille, 1825
                     01 Genus Cassis Scopoli, 1777
                     02 Genus Casmaria Adams & Adams, 1853
                     03 Genus Phalium Link, 1807
                     04 Genus Cypraecassis Stutchbury, 1837
                     05 Genus Sconsia Gray, 1847
                     06 Genus Dalium Dall, 1889
                     07 Genus Morum Röding, 1798
                     08 Genus Galeodea Link, 1807
                     09 Genus Morionella Dall, 1909 see Subgenus Morionella Dall, 1909
                     10 Genus Taieria Finlay & Marwick, 1937