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 Arminoidea Iredale & O'Donoghue, 1923 (1841) see Suborder Arminina Odhner, 1934
                   Superfamily Pachygnatha
                     1 Family Madrellidae Preston, 1911
                     2 Family Dironidae Eliot, 1910
                     3 Family Zephyrinidae Iredale & O'Donoghue, 1923 see Family Proctonotidae Gray, 1853