Ancient sea once split North America, its creatures still shine like gems
The Smithsonian's National Museum of Natural History is showcasing fossils from the Western Interior Seaway, an ancient sea that once split North America. These fossils, including shimmering ammonite shells, provide a window into the diverse marine life that existed 70 million years ago.
Why it matters
These findings offer significant scientific insights into prehistoric ecosystems and the geological history of the North American continent.
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 more than 70 million years ago, the area looked completely different. Much of what is now South Dakota lay beneath a vast inland sea called the Western Interior Seaway. The sea stretched through the middle of North America and split the continent into two. Its waters were home to giant marine reptiles, sharks and ammonites, sea animals related to today's squid and octopus.Even though the sea disappeared millions of years ago, it left behind remarkable clues.
Get smarter about the news
Sign up free for a feed built around what you actually care about, Dive Deeper research on any story, and the full text of every article.
Create free accountAlready have an account? Sign in