Richard Norris is a paleontologist at Woods Hole Oceanographic Institution, and was on the drilling expedition that found conclusive proof of an immense sixty five million year old asteroid crater. He tells Jim Fleming that the collision had the force of a hundred million nuclear bombs and was definitely the cause for the extinction of the dinosaurs.

Paleontologist Philip Currie is a curator at the Royal Tyrell Museum of Paleontology in Alberta. He tells Steve Paulson that the recent discovery of a feather fossil in China is more proof that dinosaurs evolved into birds. But, ornithologist Alan Fedducia of the University of North Carolina, tells Judith Strasser that it's only their desperation to see living dinosaurs that causes paleontologists to see T-Rex at the backyard birdfeeder. He says birds have nothing in common with dinosaurs.

Tom Mitchell teaches literature at the University of Chicago. He talks with Steve Paulson about the cultural meanings of dinosaurs. He says they're portrayed as both big and small, fierce and cuddly and serve as a kind of national symbol.