The Judith River Group is a group of

geologic Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Eart ...

formations in western

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

dating from the late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

and noted as a site for the extensive excavation of

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

fossils. The formation is named after the

Judith River The Judith River is a tributary of the Missouri River, approximately 124 mi (200 km) long, running through central Montana in the United States. It rises in the Little Belt Mountains and flows northeast past Utica and Hobson. It is ...

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...

. The group is also called the Judith River Wedge. It is stratigraphically equivalent with the

Belly River Group The Belly River Group is a stratigraphical unit of Late Cretaceous age in the Western Canadian Sedimentary Basin. It takes the name from the Belly River, a tributary of the Oldman River in southern Alberta, and was first described in outcrop o ...

Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...

. It comprises the

Judith River Formation The Judith River Formation is a fossil-bearing geologic formation in Montana, and is part of the Judith River Group. It dates to the Late Cretaceous, between 79 and 75.3 million years ago, corresponding to the "Judithian" land vertebrate age. It ...

in north central Montana, as well as the Foremost,

Oldman Oldman may refer to: People * Oldman (king) (died 1687), King of the Miskito Nation *Albert Oldman (1883–1961), British boxer * C. B. Oldman (1894–1969), English bibliographer *Gary Oldman (born 1958), British actor * Hugh Oldman (1914–1988), ...

, and

Dinosaur Park Dinosaur Park is a tourist attraction in Rapid City, South Dakota, United States. Dedicated on May 22, 1936, it contains seven dinosaur sculptures on a hill overlooking the city, created to capitalize on the tourists coming to the Black Hills to s ...

formations in

and

Saskatchewan Saskatchewan ( ; ) is a Provinces and territories of Canada, province in Western Canada, western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on t ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

. Within Canada, the name term Belly River Group is more widely used for what is essentially the same stratigraphic interval as the Judith River. The wedge is exposed discontinuously in river drainages.

External links

Geologic groups of Montana Stratigraphy of Alberta Stratigraphy of Saskatchewan {{Saskatchewan-geo-stub