Abstract

Protoceratopsians are best known in North America from associated skeletal material of Montanoceratops from the early Maastrichtian of Montana and Campanian of Alberta and Leptoceratops from the late Maastrichtian of Alberta and Wyoming. We report here the first occurrence of protoceratopsian elements from the middle Campanian (Dinosaur Park Formation) of Alberta. The specimens consist of a fragmentary right dentary and an almost complete left dentary which can be referred to Leptoceratops sp. Recent examination of Albertan microvertebrate material has identified cf. protoceratopsians teeth from the latest Santonian (Milk River Formation), extending the record of Albertan protoceratopsians back almost 20 million years. The rarity of these small ornithischians in the fossil record of Alberta may have been due to ecological exclusion from the wet, coastal environments that were preferred by the larger, more abundant ceratopsids.