Pangea, the neverending world

Once upon a time, millions of years ago, dinosaurs ruled the Earth.
Some of them were as small as birds, others weighed as much as fourteen elephants.
One day, they went extinct.
Watch the video and, perhaps, you will understand why they disappeared ?????.

[youtube]http://www.youtube.com/watch?v=OwKfm57OcjQ[/youtube]