Kingdom Animalia Linnaeus, 1758 - animals
   Phylum Nematoda Gegenbaur, 1859 - round worms
     Class Dorylaimea Hodda, 2007
       Subclass Bathyodontia Hodda, 2007 [monotypic]
         Superorder Mononchica Hodda, 2007
           Order Mermithida Hyman, 1951
             Suborder Mermithina Andrassy, 1971
               Superfamily Mermithoidea Braun, 1883
                 Family Tetradonematidae Cobb, 1919