North Dakota Stratigraphy latifrons ROCK ROCK UNIT COLUMN PERIOD AGES MILLIONS OF YEARS AGO Common Name: Oahe .01 Giant Ice Age bison

Coleharbor QUATERNARY Classification: 1.8 Pliocene Unnamed 5 Miocene Class: Mammalia 25 Arikaree Order: Artiodactyla Family: Brule Oligocene

38 South Heart This specimen, the only Bison latifrons skull ever found in North Chadron Chalky Buttes Dakota, was discovered by Kent Pelton of Watford City on U. S. Camels Butte Eocene Golden 55 Valley Bear Den Army Corps of Engineers administered land within the Fort Berthold Reservation near New Town. Bone from this fossil was Sentinel radiocarbon dated indicating that it is over 47,500 years old. It is Butte

TERTIARY on display at the North Dakota Heritage Center in Bismarck. Funding for restoration of the skull was provided by the U. S. Army Corps of Engineers, Omaha District, Garrison Project. Skull Bullion is 2.2 m wide. ND State Fossil Collection. Paleocene Creek

Slope Description:

Cannonball The scientific name Bison latifrons is derived from the Greek language and refers to this bison’s broad cranium and large horns. Ludlow 65 They were huge , the largest of all North Hell Creek with horn cores that spanned over 200 cm compared with horn core spans of about 65 cm for the living North American bison. Fox Hills They were about 25% larger than the living bison. Bison latifrons lived in North Dakota during the last Ice Age at the same time that mammoths and mastodons lived here. Bison latifrons inhabited ACEOUS Pierre forest openings and woodland areas unlike the grassland-dwelling CRET modern bison. They lived in small groups unlike the herding

84 modern bison. Bison latifrons became extinct during the last Ice Niobrara Age several thousand years ago. Carlile

Carbonate Calcareous Shale Claystone/Shale

Siltstone Sandstone Sand & Gravel

Mudstone Lignite Glacial Drift

Bison latifrons. Painting by, and courtesy of, Dorothy S. Norton.

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