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
       1 Cephalorhyncha Malakhov, 1980 see [unranked] Scalidophora Lemburg, 1995
       2 Nematoida Rudolphi, 1808