What Really Killed The Dinosaurs | BBC Earth

the dinosaurs were some of the most successful animals ever to roam the planet for a hundred and forty million years their dominance was unchallenged except by other dinosaurs then all of a sudden they all disappeared something must have killed them off to find out what had done it scientists began to investigate a layer of rock formed 65 million years ago it's seen in mines and rock outcrops around the world below this layer there are lots of dinosaur fossils above it there are none it's called the KT boundary this is the KT boundary because it's such a thin sharp line we know something dramatic must have happened to you some catastrophe and until recently we have almost no clue what happened whatsoever here so to remain a total mystery then in 1979 they discovered a clue in the KT boundary a high concentration of an element called iridium such quantities are extremely rare on earth and usually come from outer space so soon we should find 10,000 times more iridium at the very moment when the dinosaurs disappeared you know somewhere on earth a very big impact must have happened by an asteroid or a comet in fact there was so much iridium scientists realized the asteroid must have been a staggering 10 kilometers in diameter if the theory was right the impact would have created a fireball equivalent to 10 billion Hiroshima bombs the shockwave alone would have destroyed all life for hundreds of miles around you

Channel: BBC Earth

Views: 628,517

Rating: 4.5938969 out of 5

Keywords: what really killed the dinosaurs, did a meteor kill the dinosaurs, what killed the dinosaurs, do we know what killed the dinosaurs, how did dinosaurs die, how did the dinosaurs die, where did dinosaurs go, dinosaur, dinosaurs, dinosaur extinction, extinction of dinosaurs, bbc earth, bbc

Id: JqGphEaJvDE

Length: 3min 8sec (188 seconds)

Published: Wed Aug 24 2011