The Dinosaur and the cosmic collision

The great dinosaurs dominated the earth 140 million years ago but their reign was abruptly and mysteriouly ended 65 million years ago at the end of the Cretaceous Period. This program posits the theory that the dinosaurs' extinction was caused by a cataclysmic cosmic collision, an asteroid which fell to earth leaving it barren and devoid of life. Cameras visit Dr. Dinosaur Jim Jensen at a dig in the fossil-rich area of western Colorado's Dry Mesa Quarry where he works to uncover a large dinosaur skeleton. Animated segments illustrate and describe the characteristics of such dinosaurs as Ultrasaurus, Brontosaurus, Stegasaurus and Tyrannosaurus Rex. In the limestone gorge behind the Italian town of Gubbio, Professor Walter Alvarez discusses a geological discovery he made while taking a sampling of layered rock formations. Between layers of limestone, indicative of microscopic life, Alvarez detected a layer of clay. Analyzing the unusual deposit, Alvarez's physicist father, Louis, discovered high amounts of irridium, supporting the cosmic collison theory. Dr. Eugene Shoemaker of the U.S. Geological Survey delineates the effects of an asteroid crash. Despite convincing evidence, some scientists dispute the collision theory stating that the earth has experienced mass extinctions at regular intervals throughout its existence.