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 Rhigonematoidea Artigas, 1930
                 Family Xustromatidae Hodda, 2011, nom. null. see Family Xustrostomatidae Hunt, 2002