Several species went extinct before the impact 66 million years ago, adding to evidence that volcanoes were a culprit in the mass die-off.
What killed the dinosaurs? Few questions in science have been more mysterious—and more contentious. Today, most textbooks and teachers tell us that nonavian dinosaurs, along with three-fourths of all species on Earth, disappeared when a massive asteroid hit the planet near the Yucatán Peninsula some 66 million years ago.
But a new study published in the journal Geology shows that an episode of intense volcanism in present-day India wiped out several species beforethat impact occurred.
The result adds to arguments that eruptions plus the asteroid caused a one-two punch. The volcanism provided the first strike, weakening the climate so much that a meteor—the more deafening blow—was able to spell disaster for Tyrannosaurs rex and its late Cretaceous kin.