K-Pg is the extinction event at the end of the Cretaceous which Planet Dinosaur would have us believe is the cause for the dinosaurs' death.
The Great Survivors:
The entrance of the comet is preceded with a sad speech by John Hurt. Mournful music plays in the background as John Hurt narrates how successful the dinosaurs were. Then he says one line with horrible clarity: 'But they were doomed.' Suddenly a huge comet spirals out of nowhere and hurtles towards the Earth with a speed twenty times that of a bullet. John Hurt narrates the catastrophic consequences that follow as they happen on screen. Finally, molten rock rains out of the sky and the planet is cloaked in a blanket of darkness. The K-Pg was a test, a test for survival that the dinosaurs failed. The K-Pg used the dinosaurs' size and put it against them, condemning them to extinction. Then the episode ends and the K-Pg is never seen again.
1. The 'K' in K-Pg stands for 'Cretaceous.'