An asteroid impact, not volcanism, may have made Earth unlivable for dinosaurs
For decades, scientists have gone back and forth about whether massive volcanic eruptions or an asteroid impact — or maybe both — caused a mass extinction that saw the demise of all nonbird dinosaurs about 66 million years ago. Now, geologic evidence and data on dinosaur habitats, combined with climate and ecological simulations, suggest it wasn’t the volcanism. Instead, a decades-long cold winter triggered by the giant impact wiped out dinosaur habitats and made it impossible for the creatures to survive, researchers report June 29 in Proceedings of the National Academy of Sciences. In a plot twist, volcanism at the Deccan Traps, in what is now India, may have actually ameliorated the negative effects of the long winter, warming the planet quicker than would have occurred otherwise and allowing mammals room to thrive, the researchers say. “It’s a complete change in the narrative of Deccan volcanism … [which] may well have been the...