The mass extinction that took out the dinosaurs was already well underway by the time a six-mile asteroid slammed into Mexico’s Yucatán Peninsula 65 million years ago, it appears.
New University of Washington research indicates that life on the sea floor was already dying, thanks to volcanic eruptions on India’s Deccan Plateau that warmed the planet and killed life on the ocean floor. “The eruptions started 300,000 to 200,000 years before the impact, and they may have lasted 100,000 years,” says doctoral student Thomas Tobin.