A groundbreaking article that could provide a fresh new explanation for the extinction of the Ice Age megafauna......
http://www.theregister.co.uk/2013/09/03/canadian_comet_impact_fingered_for_triggering_younger_dryas_climate_shift/
With debate still ongoing over why the Ice Age mammals went extinct, the possible discovery of the remnants of an extraterrestrial object in Canada dating back 13,000 years ago may bolster the opinions of scientists who believe that the cavemen weren't totally responsible for the extinction of the imperial mammoths, the ground sloths, and the saber-toothed cats. If an extraterrestrial impact in Canada triggered climate change at the end of the Ice Age, then it may have been a Chicxulub moment for the wooly mammoths, the saber-toothed cats, and the ground sloths.