South Dakota Fossils

South Dakota, along with neighboring Montana are particularly known for its dinosaur fossils. The Cretaceous Hell Creek Formation in Harding County, South Dakota is particularly famous. These badlands were among those where the famous paleontologists, Cope and Marsh, held there bone wars. of the American West. Dinosaurs such as Triceratops and Tyrannosaurus have been discovered there. Beautiful iridescent scaphites ammonites are found in the Cretaceous Fox Hills Formation in north central South Dakota. South Dakota during the during the Cretaceous bordered a vast and shallow inland sea extending from what is now the Gulf of Mexico well up into Canada. Ammonites thrived in this sea while huge dinosaurs roamed the land.