Kingdom Animalia Linnaeus, 1758 - animals
   Phylum Nematoda Gegenbaur, 1859 - round worms
     Class Chromadorea Inglis, 1983
       Subclass Plectia Hodda, 2007
         Superorder Plectica Hodda, 2007
           Order Leptolaimida Hodda, 2007 [monotypic]
             Suborder Leptolaimina Lorenzen, 1981
               Superfamily Leptolaimoidea Oerley, 1880
                 1 Family Aegialoalaimidae Lorenzen, 1981
                 2 Family Aphanolaimidae Chitwood, 1936
                 3 Family Diplopeltoididae Tchesunov, 1990
                 4 Family Leptolaimidae Oerley, 1880
                 5 Family Ohridiidae Lorenzen, 1981
                 6 Family Paramicrolaimidae Lorenzen, 1981
                 7 Family Rhadinematidae Lorenzen, 1981