A group of fossil hunters uncover not only the bones of a 77 million year old dinosaur, but its mummified and fossilized 'body'. After excavating the duckbill nicknamed 'Leonardo', scientists begin a battery of tests including a radiographic autopsy. Journey along with a team of paleontology experts as they make several astonishing discoveries including the creature's last meal and never-before-seen internal organs.

As dinosaurs grew into the behemoths of the Cretaceous period they evolved many extraordinary but apparently useless features including spikes, sails horns, crests and the tiny "arms" of tyrannosaurs. The program reviews these unusual features and discusses theories of why they exist.