The demise of the dinosaurs remains a mystery -- but one of the most popular theories suggests that a massive asteroid slammed the earth 65 million years ago, blackening the sky and cooling the land, while releasing toxic substances into the air.
Now, researchers at Princeton University believe the mass extinction was conceived here on Earth.
A new study, presented earlier this month at a Geophysical conference in San Francisco, suggests that volcanoes erupting near present-day Mumbai may have spewed sulfur and carbon dioxide into the atmosphere, rendering it toxic and leading to global warming.
Gerta Keller, a geologist at Princeton University who conducted the study, said that the findings call for a "reassessment" of what happened to the dinosaurs.
Researchers used fossil records found by oil companies drilling off the coast of eastern India in 2009. Keller and her team discovered sediment filled with ancient lava as well as fossils that date back to the time the dinosaurs vanished. The fossils began to get smaller and less elaborate, suggesting that volcanic activity prompted ocean acidification, leading to the gradual eradication of marine life.
Similar results were discovered in the Middle East, Europe and North America.
Land fossils of plants and animals from the same era appear to have "vanished", suggesting that extinctions were taking place on land as well.
While a previous study bore evidence of iridium - a chemical associated with asteroids - Keller and her team say the impact occurred after the die-offs began. Researchers believe the asteroid could have exacerbated the problem, but it was not the cause, adding that the meteorite would have been too small to have caused the extinction.