~66 million years agoReputable sourceWell documented
The Asteroid: The End-Cretaceous Extinction
On the timeline · around ~66 million years ago · Cenozoic
What happened
An asteroid roughly 10 kilometres wide struck at Chicxulub, on today's Yucatán Peninsula, about 66 million years ago. The impact darkened the skies for years and caused a global catastrophe that killed around three-quarters of all species, including every non-avian dinosaur.
Why it matters
The end-Cretaceous extinction ended the age of dinosaurs and cleared ecological space for the mammals — and ultimately for humans.
Sources
- Natural History Museum. How an asteroid ended the age of the dinosaurs · Reputable source