66 million years ago, a large asteroid crashed into Earth near Mexico's Yucatán Peninsula, sparking a frigid global winter that led to the mass extinction of dinosaurs who had reigned over the planet for over 160 million years.
"The asteroid didn't kill all the dinosaurs in one go, but it was a more stealthy murderer, which triggered a war of attrition that led three out of every four species to die," Steve Brusatte, a paleontologist at the University of Edinburgh unaffiliated with the new study, told Guardian's Ian Sample.
