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 Thecosomata Blainville, 1824 - shelled pteropods see Suborder Thecosomata Blainville, 1824
                 Suborder Pseudothecosomata Meisenheimer, 1905 see Infraorder Pseudothecosomata Meisenheimer, 1905
                   1 Family Peraclidae Tesch, 1913
                   2 Family Cymbuliidae Gray, 1840
                   3 Family Desmopteridae Chun, 1889