[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Kingdom Animalia Linnaeus, 1758 - animals
     Branch Eumetazoa Butschli, 1910 see [unranked] Eumetazoa Bütschli, 1910
       Division Bilateria Hatschek, 1888 see Subkingdom Bilateria Hatschek, 1888
         Subdivision Protostomia Grobben, 1908 see Infrakingdom Protostomia Grobben, 1908
           Section Eucoelomata see Superphylum Eucoelomata
             Phylum Annelida Lamarck, 1809 - segmented worms
               Class Hirudinea Lamarck, 1818 - leeches see Subclass Hirudinida
                 Order Gnathobdellida
                   Genus Hirudo Linnaeus, 1758
                     Hirudo medicinalis Linnaeus, 1758