An ancient sea once divided North America from north to south; 70-million-year-old creatures from its waters still shimmer like gemstones
Fossils from this period are displayed at the Smithsonian’s National Museum of Natural History. South Dakota is one of the most landlocked states in the United States. It is more than 1,000 miles away from both the Pacific and Atlantic oceans. It is hard to imagine that this dry landscape was once covered by water.But…
