Keywords: Monoclonius sphenocerus.png en Holotype specimens of Monoclonius crassus 1 AMNH 3998 and M sphenocerus 2 AMNH 3989 1889-01-01 http //biodiversitylibrary org/page/41651518 page/749/mode/1up Edward Drinker Cope other versions PD-old-70-1923 Monoclonius Ornithischia type specimens |