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 Anaspidea Fischer, 1883 - sea hares
                 1 ?Family Akeridae Mazzarelli, 1891
                 2 Family Aplysiidae Lamarck, 1809
                 3 Family Dolabellidae see Subfamily Dolabellinae Pilsbry, 1895
                 4 Family Dolabriferidae Pilsbry, 1895 see Subfamily Dolabriferinae Pilsbry, 1895
                 5 Family Notarchidae see Subfamily Notarchinae Mazzarelli, 1893