Opisthokonta Cavalier-Smith 1987, nom. cl. inval. see Clade Opisthokonta Cavalier-Smith 1987 [Simpson & Medina 2020]
   Metazoa Haeckel 1874 - multicellular animals see Kingdom Animalia Linnaeus, 1758
     Epitheliozoa Ax, 1996
       Eumetazoa Bütschli, 1910 - eumetazoans
         Acrosomata Ax, 1996 see [unranked] Eumetazoa Bütschli, 1910
           Bilateria Hatschek, 1888 - bilaterians see Subkingdom Bilateria Hatschek, 1888
             Protostomia Grobben, 1908 see Infrakingdom Protostomia Grobben, 1908
               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]
                 Cycloneuralia Nielsen, 1995 see [unranked] Introverta Nielsen, 1995
                   Scalidophora Lemburg, 1995
                     1 Priapulida Delage & Hérouard, 1897 - priapulids
                     2.1 Kinorhyncha Reinhard, 1887 - kinorhynchs
                     2.2 Loricifera Kristensen, 1983 - loriciferans