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 Ascaridina Inglis, 1983
               1 Superfamily Ascaridoidea Baird, 1853
               2 Superfamily Cosmocercoidea Railliet, 1916
               3 Superfamily Heterakoidea Railliet & Henry, 1912
               4 Superfamily Seuratoidea Hall, 1916
               5 Superfamily Subuluroidea Travassos, 1914