Paleontology in North Dakota

Climate gradually cooled until the Ice Age, when glaciers entered the area and mammoths and mastodons roamed the local woodlands.

Local Native Americans interpreted fossils as the remains of the water monster Unktehi or burrowing serpents killed by the thunderbirds.

Sea levels continued to fluctuate throughout the remainder of the Paleozoic, and by the Permian period significant areas of the state were dry land.

[1][2] The Niobrara Formation of the Pembina Escarpment and Valley City region records the presence of fish during the Cretaceous with fossils of their scales and bones.

[1] Rich North Dakotan forests included plants like cycads, dawn redwoods, ferns, figs, and palms.

[1] When the Sioux lived around the Great Lakes, they imagined their mythical Water Monster Unktehi as a large aquatic buffalo-like mammal.

This image was likely derived from early observations of large Pleistocene mammal fossils like mammoths and mastodons eroding out of the banks of local lakes and rivers.

[6] As some groups of Sioux began moving west into the regions that includes North Dakota their depictions of Unktehi tended to converge on the characteristics of local fossils.

[7] The Sioux of the Standing Rock Reservation, which straddles the border between North and South Dakota, have a long history of familiarity with dinosaur bonebeds.

[8] The first scientifically documented fossils in North Dakota were collected during the Lewis and Clark Expedition between 1804 and 1806 as they mapped the course of the Missouri River.

The first fossil written about in the state were petrified wood preserved in sandstone concretions discovered at the Cannonball River.

In 1833 a German named Alexander Philip Maximilian observed leaf impressions preserved in sandstone in the upper Missouri River area.

In 1843 John James Audubon collected fossils like petrified wood and marine shells in the area but the specimens were of low quality.

[3]: 225–226 Evans sent vertebrate fossils to Joseph Leidy, who discussed the remains in a pioneering and historically significant series of publications.

New York geologist W. James Hall became interested in North Dakota paleontology as a result of Evans and Leidy's research.

[3]: 227  In the summer of 1963, Charles I. Frye discovered a specimen of Triceratops in the Hell Creek Formation of Slope County near the town of Marmarth.

Among the excavators were Dr. Holland, Jack W. Crawford, and Michael F. Archbold from the Department of Geology at the University of North Dakota at Grand Forks.