The Cretaceous in North Dakota, US

Cretaceous in North Dakota map

Choose a time period:


Cretaceous Fossils

No slide show is available for the Cretaceous in North Dakota.

Search the fossil gallery

Paleontology and geology

During the Cretaceous, North Dakota was either completely or partially covered by a warm, shallow sea called the Western Interior Seaway. Although sea level fluctuated, it was never very deep, perhaps a few hundred feet at most, and at its greatest extent connected the Arctic Sea with the Gulf of Mexico. As the rising Rockies to the west were being eroded, rivers carried sediment eastward into the Seaway, creating large deltas in the western part of North Dakota. Changes in sea level resulted in a fluctuating shoreline and at lowest levels created shoreline habitats in central North Dakota. Fine-grained sediments, mostly silt and clay, were deposited on the seafloor. Entombed in these rocks are fossils of marine reptiles, including the mosasaur Plioplatecarpus, plesiosaurs, and the sea turtle, Archelon, as well as sharks, rays, ratfish, birds, and numerous marine invertebrates.

Links to more on the Cretaceous in North Dakota

Organizations | Resources


Societies and Clubs (showing 1 of 1 listings)

North Dakota Geological Survey Fossil Resource Program: Links to all varieties of information on North Dakota paleontology, including research papers, museums, and background information on the state's fossils.

top Top of List

Museums (showing 1 of 1 listings)

The Pioneer Trails Regional Museum: Located in Bowman, North Dakota, PTRM hosts exhibits about local Cretaceous, Paleocene, and Eocene fossils. This museum also has an active research program.

top Top of List


Field Guides (showing 1 of 1 listings)

Oceans of Kansas: Photographs, artwork, historical papers, and other information on the sea creatures, especially mosasaurs and plesiosaurs, that lived in the Western United States during the Cretaceous period.

top Top of List

Montana State Map
South Dakota State Map
Minnesota State Map
Saskatchewan Province Map
Manitoba Province Map

site tour | about the site | site map | site credits | page credits | help | FAQs | contact
© | editorial policy | awards | teachers' guide | site generator | About RSS

paleontology news:   recent site additions: