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 Camallanoidea Railliet & Henry, 1915
                 1 Family Camallanidae Railliet & Henry, 1915
                 2 Family Physalopteridae Railliet, 1893