Genus MONOCLONIUS
Kingdom / Phylum . . . . . . . . Subphylum / Superclass . . . . Class / Subclass . . . . . . . . . . Infraclass / Division. . . . . . . . Subdivision / Infradivision . . . Superorder / Order. . . . . . . . Suborder / Infraorder . . . . . . Superfamily / Family . . . . . . . Subfamily / Genus . . . . . . . . .	Animalia / Chordata Cephalochordata / Gnathostomata Reptilia / Diapsida Archosauromorpha / Archosauria Avemetatarsalia / Ornithodira Dinosauria / Ornithischia Ceratopsia / n.a. n.a. / Ceratopsidae Centrosaurinae / Monoclonius
Age: Distribution:	Late Cretaceous North America
Depicted on: Angola, 1998 (position 8 of sheet 2) Bulgaria, 2003 (0,65 L. and in stamp booklet) Central African Republic, 2001 (position 1 of sheet 2) Cuba, 1985 (8 c.) Dominica, 1995 (20 c., but Centrosaurus depicted) Gabon, 1995 (position 12 of sheet 1) Ghana, 1999 (position 4 of sheet 1) Georgia, 1995 and 1998 (position 7 of sheet, as Mastodon in 1998 issue) Guinea-Bissau, 2015 (position 3 of sheet, as Centrosaurus) Guinea-Bissau, 2021 (M.S. 1 margin) Maldives, 1992 (5 R., but Centrosaurus depicted) Mozambique, 2002 (position 4 of sheet 1, but Centrosaurus shown) Niger, 2022 (M.S. 1 margin, but Centrosaurus shown) Sao Tome e Principe, 2003 (5000 Db. and M.S. margin) Sierra Leone, 1995 (400 L., but Centrosaurus shown) Turks and Caicos Islands, 1993 (M.S. 1 margin, as Centrosaurus) Zambia, 1999 (position 7 of sheet 2, as Centrosaurus)   Note: Considered to be synonymous with Centrosaurus by some experts.