[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Enterozoa
     Grade Cœlomata
       Phylum Appendiculata {Lankester}
         Branch Gnathopoda Straus-Durkheim, 1829
           Grade Condylopoda
             Class Arachnida Lamarck, 1801
               Metarachnæ
                 1 Order Linguatulina
                 2 Order Tardigrada Doyère, 1840 see Phylum Tardigrada Doyère, 1840
                 3 Order Pycnogonida Latreille, 1810 see Class Pycnogonida Latreille, 1810