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 Annelida Lamarck, 1809 - segmented worms
           Class Hirudinoidea see Class Clitellata Michaelsen, 1919
             1 Subclass Branchiobdellida see Subclass Branchiobdellidea
             2 Subclass Acanthobdellida see Subclass Acanthobdellidea Livanow, 1905
             3 Subclass Hirudinea see Subclass Euhirudinea Lukin, 1956