Dinosaurs Episode 6 - Death of a Dynasty

At the end of the Cretaceous Period, 65 million years ago, all the dinosaurs died out. The question of why the dinosaurs went extinct is one of the most frequently asked questions to all dinosaur palaeontologists. There have been many different ideas put forward as an explanation from the serious to the ridiculous. Probably the two most likely are: the regression and habitat loss hypothesis (gradualistic) or, the extraterrestrial impact hypothesis (catastrophic).