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 Nudibranchia Cuvier, 1814 - "true" nudibranchs
                 Suborder Doridoidea Rafinesque, 1815 see Suborder Doridina Odhner, 1934
                   Superfamily Anadoridacea Boss, 1982, nom. inval., orth. inval. see Superfamily Anadoridoidea Vaught, 1989, nom. inval.
                     Nonsuctoria Bergh, 1892 see Superfamily Polyceroidea Alder & Hancock, 1845
                       Family Vayssiereidae Thiele, 1931 see Family Okadaiidae Baba, 1930
                         Genus Okadaia Baba, 1930