Bilateria Hatschek, 1888 - bilaterians see Subkingdom Bilateria Hatschek, 1888
   Spiralia Schleip, 1929 - spiralians see Superphylum Spiralia Schleip, 1929
     Platyzoa Ax, 1987 see [unranked] Spiralia Schleip, 1929
       Gnathifera Ahlrichs, 1995
         1 Phylum Gnathostomulida Ax, 1956 - gnathostomulids
         2.1 Phylum Cycliophora Funch & Kristensen, 1995 - cycliophorans
         2.2 Phylum Syndermata Ahlrichs, 1995