The SDSM Vertebrate Paleontology Collection began in the late 19th century with collections of fossil fauna from the nearby White River Badlands and Western Interior Seaway exposures. Major collections include, but are not limited to, marine vertebrates and associated fauna from the Cretaceous Western Interior Seaway, terrestrial vertebrates (including dinosaurs) from Jurassic and Cretaceous sites, extensive holdings from the White River Badlands of South Dakota and Nebraska (late Eocene to mid-Oligocene), and late Tertiary to Quaternary collections from the region, including mammoths and other Pleistocene vertebrates.