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 Opisthobranchia Milne-Edwards, 1848 - opisthobranchs see Order Opisthobranchia Milne-Edwards, 1848
               Order Gymnosomata Blainville, 1824 - naked pteropods see Suborder Gymnosomata Blainville, 1824
                 Family Thliptodontidae Kwietniewski, 1902 (1902) see Subfamily Thliptodontinae Kwietniewski, 1902 (1902)
                   1 Genus Thliptodon Boas, 1886
                   2 Genus Massya Pruvot-Fol, 1924
                   3 Genus Cephalobranchia Boss, 1982, orth. inval. see Genus Cephalobrachia Bonnevie, 1913