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
             Subclass Hirudinea see Subclass Euhirudinea Lukin, 1956
               Order Arhynchobdellae see Order Arhynchobdellida Blanchard, 1894
                 Family Hirudinidae Whitman, 1886
                   Genus Hirudo Linnaeus, 1758
                     Hirudo medicinalis Linnaeus, 1758