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 Cnidaria Hatschek, 1888 - cnidarians Tesserazoa Salvini-Plawen, 1978