[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Enterozoa
     Grade Cœlomata
       Phylum Appendiculata {Lankester}
         Branch Rotifera
           Class Rotifera
             Order Chœtoptera
               1 Genus Triarthra Ehrenberg, 1832
               2 Genus Polyarthra Ehrenberg, 1834