A long lasting debate on whether an asteroid impact caused the extinction of dinosaurs gained momentum after new evidence on the same was found.
It was believed for some time now that when a massive asteroid smashed into what is now Mexico's Yucatan Peninsula, it cooled down the temperature of the earth and wiped out the dinosaur race.
New findings now suggest that the K-T event (mass wipeout of dinosaurs globally) and the Chicxulub collision (asteroid impact) occurred 33,000 years apart. Hence, scientists have begun to question whether dinosaurs became extinct before the collision.
"Our work basically puts a nail in that coffin," geologist Paul Renne of the University of California Berkeley said. "The previous data that we had ... actually said that they (the tektites and the ash) were different in age, that they differed by about 180000 years and that the extinction happened before the impact, which would totally preclude there being a causal relationship."
"It's gratifying to see these results, for those of us who've been arguing a long time that there was an impact at the time of this mass extinction," geologist Walter Alvarez at the University of California at Berkeley, who did not participate in this study, told LiveScience. "This research is just a tour de force, a demonstration of really skillful geochronology to resolve time that well."
Previously it was believed that the asteroid impact and the extinction took place simultaneously in time.
"The impact was clearly the final straw that pushed Earth past the tipping point," Renne said. "We have shown that these events are synchronous to within a gnat's eyebrow, and therefore, the impact clearly played a major role in extinctions, but it probably wasn't just the impact."
Renne said the best way to find out which side of the debate is actually true is to understand what was happening before the asteroid impact took place. Study on the levels of ecological stress should also be done to discover what led to the extinction of the dinosaurs.
The scientists detailed their findings in the Feb. 8 issue of the journal Science.
