Fossil leaves yield extinction clues
By Sid Perkins
Analyses of fossil leaves provide more evidence that the mass extinction that wiped out the dinosaurs 65 million years ago was sudden and probably brought about by an extraterrestrial impact.
The demise of the dinosaurs coincided both with a major extraterrestrial impact and massive volcanism in India. Both of those events–one sudden, the other unfolding over as many as 2 million years–would have dramatically influenced Earth’s climate by pumping carbon dioxide and other gases into the atmosphere. Some scientists have proposed that volcanism alone was enough to have caused the extinctions.