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Jefferson National Expansion Memorial
Photo Album October 26, 1804
Dinosaur cartoon  

Did You Know?
On September 10, 1804 on Cedar Island, in South Dakota, William Clark discovered the fossilized remains of the ribs, backbone and teeth of a plesiosaur. Plesiosaurs were animals who lived at the same time as the dinosaurs, but swam rather than walking on land. Clark thought it was a giant fish bone!
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Last Updated: April 25, 2008 at 12:39 EST