For decades, scientists have debated exactly what kind of cataclysm was responsible for the extinction of the dinosaurs. Did a giant rock from outer space blast T. rex and his ilk off the face of the Earth? Or was a huge volcanic eruption to blame? Now the jury is in — maybe. In Friday’s issue of the prestigious journal Science, a “dream team” of 41 researchers from 12 nations declares that the evidence points overwhelmingly to a mountain-sized asteroid that walloped the planet 65 million years ago. The monstrous boulder left an equally monstrous scar, a 120-mile-wide dimple known as the Chicxulub crater on the Mexican coast.

“We assessed the whole picture,” says Kirk Johnson of the Denver Museum of Nature and Science. “The answer is quite simple. … The Chicxulub crater really is the culprit.”