Asteroid may have killed dinosaurs quicker than scientists
thought CAPE CANAVERAL, Florida | CAPE CANAVERAL, Florida
(Reuters) - Dinosaurs died off about 33,000 years after an
asteroid hit the Earth, much sooner than scientists had
believed, and the asteroid may not have been the sole cause of
extinction, according to a study released Thursday. Earth's
climate may have been at a tipping point when a massive asteroid
smashed into what is now Mexico's Yucatan Peninsula and
triggered cooling temperatures that wiped out the dinosaurs,
researchers said. The time between the asteroid's arrival,
marked by a 110-mile-(180-km-)wide crater near Chicxulub,
Mexico, and the dinosaurs' demise was believed to be as long as
300,000 years. The study, based on high-precision radiometric
dating techniques, said the events occurred within 33,000 years
of each other. Other scientists had questioned whether dinosaurs
died before the asteroid impact. "Our work basically puts a nail
in that coffin," geologist Paul Renne of the Unive