Bilateria Hatschek, 1888 - bilaterians see Subkingdom Bilateria Hatschek, 1888
   Ecdysozoa Aguinaldo, Turbeville, Linford, Rivera, Garey, Raff & Lake 1997, nom. cl. inval. - ecdysozoans see Clade Ecdysozoa Aguinaldo, Turbeville, Linford, Rivera, Garey, Raff & Lake 1997 [Lake, Halanych, Servin & Garey 2020]
     Introverta Nielsen, 1995
       Cephalorhyncha Malakhov, 1980 see [unranked] Scalidophora Lemburg, 1995
         1 Phylum Priapulida Delage & Hérouard, 1897 - priapulids
         2 Phylum Kinorhyncha Reinhard, 1887 - kinorhynchs
         3 Phylum Loricifera Kristensen, 1983 - loriciferans