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
             1 Suborder Ascaridina Inglis, 1983
             2 Suborder Dracunculina Hodda, 2007
             3 Suborder Gnathostomatina Skrjabin & Ivaschkin, 1973 [monotypic]
             4 Suborder Oxyurina Railliet, 1916
             5 Suborder Rhigonematina Inglis, 1983
             6 Suborder Spirurina Railliet & Henry, 1915