Kingdom Animalia Linnaeus, 1758 - animals
   Phylum Nematoda Gegenbaur, 1859 - round worms
     Class Chromadorea Inglis, 1983
       Subclass Plectia Hodda, 2007
         Superorder Rhabditica Hodda, 2007
           Order Rhabditida Chitwood, 1933
             Suborder Rhabditina Chitwood, 1933
               Superfamily Strongyloidea Baird, 1853
                 1 Family Ancylostomatidae Looss, 1905
                 2 Family Metastrongylidae Leiper, 1908
                 3 Family Strongylidae Baird, 1853
                 4 Family Trichostrongylidae Leiper, 1908