The Cretaceous-Tertiary Mass Extinction Event is an event that kills nearly all the reptiles on earth, including reptilian dinosaurs. This happened 65,000,000 years ago. Only one group of dinosaurs survives, not
reptiles but birds. An asteroid is believed to wipe out the 75 percent of life that died out. In Prehistoric Park, Nigel saves Terrence and Matilda just before the shock waves from the asteroid reaches Montana!