Kingdom Animalia Linnaeus, 1758 - animals
   Phylum Nematoda Gegenbaur, 1859 - round worms
     Class Chromadorea Inglis, 1983
       Subclass Plectia Hodda, 2007
         Superorder Rhabditica Hodda, 2007
           Order Spirurida Railliet, 1914
             Suborder Spirurina Railliet & Henry, 1915
               Superfamily Spiruroidea Oerley, 1885
                 1 Family Gongylonematidae Hall, 1916
                 2 Family Hartertiidae Quentin, 1970
                 3 Family Spirocercidae Chitwood & Wehr, 1932
                 4 Family Spiruridae Oerley, 1885
                 5 Family Tricheilidae Wang & Wang, 1991