Kingdom [Animalia] Linnaeus, 1758 - animals
   Subkingdom Metazoa Haeckel, 1874 see Kingdom Animalia Linnaeus, 1758
     Division Eumetazoa Butschli, 1910 see Subkingdom Eumetazoa Butschli, 1910
       Subdivision Bilateralia
         Phylum Asc-helminthes
           Class Nematoda Gegenbaur, 1859
             Subclass Secernentea
               Order Strongylida see Order Rhabditida Chitwood, 1933
                 Genus Ancylostoma Creplin, 1845
                 Genus Dictyocaulus Railliet & Henry, 1907
                 Genus Metastrongylus Molin, 1861
                 Genus Necator Stiles, 1903
                 Genus Nematodirus Ransom, 1907
                 Genus Strongylus Müller, 1780
                 Genus Syngamus