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
               Lophotrochozoa Halanych, Bacheller, Aguinaldo, Liva, Hillis & Lake 1995 - lophotrochozoans
                 Spiralia Schleip, 1929 - spiralians see Superphylum Spiralia Schleip, 1929
                   Trochozoa Beklemischev, 1944 - trochozoans
                     Eutrochozoa Ghiselin, 1988 see [unranked] Trochozoa Beklemischev, 1944
                       Neotrochozoa K.J. Peterson & D.J. Eernisse, 2001 - neotrochozoans see [unranked] Trochozoa Beklemischev, 1944
                         1 Sipuncula Rafinesque, 1814 - peanut worms see Class Sipuncula
                         2.1 Mollusca Linnaeus, 1758 - molluscs
                         2.2.1 Echiura Sedgwick, 1898 - spoon worms, echiurans see Class Echiura
                         2.2.2 Annelida Lamarck, 1809 - segmented worms