When did the dinosaurs go extinct?

The non-bird dinosaurs died out about 66 million years ago at the end of the Cretaceous period, in a mass extinction that wiped out around three-quarters of all species on Earth. The leading explanation is that a massive asteroid, roughly 10 kilometres wide, struck what is now the Yucatan Peninsula in Mexico, leaving the buried Chicxulub crater. The impact threw enormous amounts of dust and debris into the atmosphere, blocking sunlight, cooling the planet and collapsing food chains. Massive volcanic eruptions in India, the Deccan Traps, may have added to the stress. Birds are the only dinosaurs that survived and still live among us today.