ABSTRACT Dinosaur Provincial Park (DPP) was designated as a UNESCO World Heritage Site in 1979, but in 1955 the exceptional quality and abundance of dinosaur fossils were already recognized with 80 km 2 of the richest fossil beds being set aside as an Alberta, Canada, provincial park. DPP represents possibly the best window into the biology of the Late Campanian anywhere in the world. At present, more than 35 species of dinosaurs, 32 species of fish, 10 species of amphibians, 29 taxa of non-dinosaurian reptiles, 1 bird, and 20 taxa of mammals are known to have been discovered in DPP. The dinosaur fossils of DPP were first seriously collected in 1912, with many “trophy” specimens being sent to museums in Ottawa, Toronto, New York, Washington, and London among others. This initial rush of dinosaur fossil collecting persisted until the 1930s, but with declining effort and results. In the late 1960s and early 1970s, scientific study of the park resumed in earnest, and by the 1980s, the park was receiving the full attention of staff from the newly created Royal Tyrrell Museum of Palaeontology, based in Drumheller. With modern scientific thinking and techniques being applied to its dinosaurian, and especially non-dinosaurian, fossils, the park is as important a resource as ever. Hydrocarbon exploration in Alberta has contributed immensely to our knowledge of the geological history of the province during the Cretaceous, thus enabling a better understanding of the factors, both physical and biological, that contributed to the creation, preservation, and subsequent exposure of the extensive fossil resources contained within DPP.

The record of dinosaurs over the last 10 m.y. of the Cretaceous, as well as surrounding the Cretaceous-Paleogene boundary, helps to define extinction scenarios. Although Late Cretaceous dinosaur fossils occur on all present-day continents, only in North America do we find a terrestrial vertebrate fossil record spanning the Cretaceous-Paleogene boundary, although promising work may yield comparable records in South America, India, China, and Europe. For the present then, the North American record represents the proxy for our knowledge of dinosaur extinction. Over the last 10 m.y. of the Cretaceous (late Campanian to late Maastrichtian) in the northern part of the western interior of North America, the number of nonavian dinosaur species dropped from 49 to 25, almost a 50% reduction, even though a 16% greater extent of fossil-bearing exposures record the last dinosaurs in the latest Cretaceous in the western interior. Important, but less-well-exposed, nonavian-dinosaur–bearing units suggest this drop occurred around, or at least commenced by, the Campanian-Maastrichtian boundary. These losses began during climatic fluctuations, occurring during and possibly in part caused by the last major regressive cycle of the Cretaceous, which also reduced the expanse of the low coastal plains inhabited by nonavian dinosaurs. The pulse of Deccan Trap emplacement that began some time later in the latest Cretaceous was also likely a major driver of climatic change. As for the dinosaur record near the Cretaceous-Paleogene boundary, even the best-known records from North America remain enigmatic and open to interpretation. Newer studies suggest some decline in at least relative abundance approaching the Cretaceous-Paleogene boundary, but the cause (or causes) for the final extinction (if it was the case) of non-avian dinosaurs remains unresolved, although the Chicxulub impact undoubtedly played a major role.