Horizon: What Really Killed The Dinosaurs?

This eye-opening documentary investigates whether one of the best known and most glamorous scientific theories could be wrong. Until recently most scientists thought they knew what killed off the dinosaurs. It was a 10 km-wide meteorite which smashed into Yucatan in Mexico. But now there is increasing evidence the impact theory could indeed be incorrect. That suggestion has generated one of the bitterest scientific rows of recent times.