[/caption] Archeologists have been divided about whether an extraterrestiral impact blasted North America about 12,900 years ago, wreaking havoc on Earth’s surface and sending scores of species — including a pygmy mammoth and the horse — into oblivion. New clues from California’s Channel Islands should put any doubt to rest, says an international team of … Continue reading "Heat-Shocked Diamonds Provide New Clue of Horse-Killing Impact"