Paleontology and geology
The Rocky Mountains were forming to the west of South Dakota during the Cretaceous, and erosion of the rising land produced the sediments that form the Lakota and Fall River Formations, now exposed in the Black Hills region in western South Dakota. Later in the period, the land surface was pushed downward by the uplifting Rockies, and the Western Interior Seaway inundated much of the state. This seaway was inhabited by abundant invertebrates, marine reptiles, and swimming birds. Adjacent to the sea, broad coastal plains were interrupted by rivers, lakes and swamps, and were home to dinosaurs, birds, and small mammals. Great coal beds formed from plants accumulating in the swampy areas. Toward the end of the Cretaceous, mountain building progressed eastward, forming successive ranges of mountains, including the Black Hills. Sediments eroding from these ranges were carried by rivers and streams and deposited as deltas.
Education and Exhibits | Resources
Education and Exhibits
Virtual Exhibits (showing 2 of 2 listings)
Sue at Chicago's Field Museum of Natural History: Excavated in South Dakota and now on display in Chicago, Sue is the world's largest, most complete, and best preserved Tyrannosaurus rex. Take a tour of this website for detailed information about Sue.
Dinosaurs of South Dakota: This site provides an overview of the dinosaurs that lived in South Dakota during the Jurassic and Cretaceous.
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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.
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