|Holotype Specimen of P. walkeri, Royal Ontario Museum|
The Dinosaur Park Formation is the uppermost member of the Belly River Group — also known as the Judith River Group, a major geologic unit in southern Alberta.
It is an area rich in fossils. The formation contains dense concentrations of dinosaur skeletons, both articulated and disarticulated, often found with preserved remains of soft-tissues. Remains of other animals such as fish, turtles, and crocodilians, as well as plant remains, are also abundant. The formation has been named after Dinosaur Provincial Park, a UNESCO World Heritage Site where the formation is well-exposed in the badlands that flank the Red Deer River.
The Dinosaur Park Formation was deposited during the Campanian stage of the Late Cretaceous, between about 76.9 and 75.8 million years ago in what was an alluvial and coastal plain environment. It is bounded by the nonmarine Oldman Formation below and the marine Bearpaw Formation above.
The formation includes diverse and well-documented fauna including dinosaurs such as the horned Centrosaurus, Chasmosaurus, and Styracosaurus, fellow duckbills Gryposaurus and Corythosaurus, the mighty tyrannosaurid Gorgosaurus, and armoured Edmontonia, Euoplocephalus and Dyoplosaurus.
Dinosaur Park Formation is interpreted as a low-relief setting of rivers and floodplains that became more swampy and influenced by marine conditions over time as the Western Interior Seaway transgressed westward. The climate was warmer than present-day Alberta, without frost, but with wetter and drier seasons. Conifers were apparently the dominant canopy plants, with an understory of ferns, tree ferns, and angiosperms.
Some of the less common hadrosaurs in the Dinosaur Park Formation of Dinosaur Provincial Park, such as Parasaurolophus, may represent the remains of individuals who died while migrating through the region. They might also have had a more upland habitat where they may have nested or fed. The presence of Parasaurolophus and Kritosaurus in northern latitude fossil sites may represent faunal exchange between otherwise distinct northern and southern biomes in Late Cretaceous North America. Both taxa are uncommon outside of the southern biome, where, along with Pentaceratops, they are predominant members of the fauna.
Photo: Holotype Specimen: The incomplete Parasaurolophus walkeri type specimen in the Royal Ontario Museum. Location: 43° 40′ 5.09″ N, 79° 23′ 40.59″ W. Shared by MissBossy.