Choristodera (from the Greek χωριστός chōristos + δέρη dérē, 'separated neck') is an extinct order of semiaquatic diapsid reptiles that ranged from the Middle Jurassic, or possibly Triassic, to the Miocene (168 to 20 or possibly 11.6 million years...
The Cretaceous (IPA: krih-TAY-shəss) is a geological period that lasted from about 143.1 to 66 Ma (million years ago). It is the third and final period of the Mesozoic Era, as well as the longest. At around 77.1 million years, it is the ninth and...
The Cretaceous–Paleogene (K–Pg) extinction event, formerly known as the Cretaceous–Tertiary (K–T) extinction event, was a major mass extinction of three-quarters (75%) of the plant and animal species on Earth which occurred around 65.5 million years...
The Hilda mega-bonebed is a complex of fourteen probable Centrosaurus apertus bonebeds discovered near the town of Hilda in Alberta, Canada. It was first described in the scientific literature by David Eberth, Donald Brinkman, and Vaia Barkas in...
Fossil archosaur research published in 2026 includes the description of new taxa, as well as other peer-reviewed publications on discoveries related to archosaur paleontology.
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 was deposited during the Campanian stage of the Late Cretaceous, between about 76.5...
The Hell Creek Formation is an intensively studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana. The formation stretches over portions of...
The Paskapoo Formation is a stratigraphic unit of Middle to Late Paleocene age in the Western Canada Sedimentary Basin. The Paskapoo underlies much of southwestern Alberta, and takes the name from the Blindman River (paskapiw means 'He is blind' in...
Gorgosaurus ( GOR-gə-SOR-əs; lit. 'dreadful lizard') is a genus of tyrannosaurid theropod dinosaur that lived in western North America during the Late Cretaceous Period (Campanian), between about 76.5 and 73 million years ago. Fossil remains have...
This is an overview of the fossil flora and fauna of the Maastrichtian-Danian Hell Creek Formation.