When Englishman William Buckland found a large tooth in 1824, scientists began to unravel the mystery a world no one knew existed.

Cronkite heads to Montana, Wyoming and Utah, where dinosaur bones were discovered in the 1870s.

A dinosaur egg was found in the Gobi Desert in 1922. More eggs were found later in a nesting site in Montana.

The story of an unusual dinosaur with feathers found in Germany in 1861.