A 66-million-year-old question has finally been answered.
Dinosaurs were killed by asteroids, not volcanoes, experts said in a recent study. The findings support long-held beliefs that asteroids led to a years-long winter, which knocked out the prehistoric species.
“Our study confirms, for the first time quantitatively, that the only plausible explanation for the extinction is the impact winter that eradicated dinosaur habitats worldwide,” Alessandro Chiarenza said in the report, published Monday in the journal Proceedings of the National Academy of Sciences.
The asteroids collided and released particles and gases deep into the atmosphere, which would have obscured the sun for years, creating permanent winters, the study said.
“We show that the asteroid caused an impact winter for decades, and that these environmental effects decimated suitable environments for dinosaurs,” explained Chiarenza.
The only dinosaurs that would survive eventually evolved into birds.
It had long been believed that volcanic activity and eruptions caused the dinosaurs to die off, however, Chiarenza disputes this, saying volcanic activity may have actually advanced life after the asteroid collision.
“We provide new evidence to suggest that the volcanic eruptions happening around the same time might have reduced the effects on the environment caused by the impact, particularly in quickening the rise of temperatures after the impact winter,” explained Chiarenza. “This volcanic-induced warming helped boost the survival and recovery of the animals and plants that made (it) through the extinction, with many groups expanding in its immediate aftermath, including birds and mammals.”
RELATED STORIES
