Everyone knows about the mass extinction that ended the Age of Dinosaurs. About 66 million years ago, a seven-mile-wide asteroid slammed into our planet and began a mass extinction that wiped out all ...

Explore the age of the dinosaurs. Discover what the prehistoric world was like and how it changed between when dinosaurs first appeared and the mass extinction at the end of the Cretaceous Period. Non ...

Lucas Atwell CC BY-SA 3.0 Everyone knows about the mass extinction that ended the Age of Dinosaurs. About 66 million years ago, a seven-mile-wide asteroid slammed into our planet and began a mass ...