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 Rhigonematina Inglis, 1983
               Superfamily Ransomnematoidea Travassos, 1930
                 1 Family Carnoyidae Filipjev, 1934
                 2 Family Hethidae Skrjabin & Schikhobalova, 1951
                 3 Family Ransomnematidae Travassos, 1930