Asteroid Not To Blame For Pleistocene Extinction
An asteroid impact was likely not responsible for the extinction of the North American megafauna – such as mammoths, saber tooth cats, giant ground sloths and Dire wolves – along with the Clovis hunter-gatherer culture some 13,000 years ago, suggests a new study in PNAS. When the last ice age came to an end approximately 13,000 years ago and the glaciers covering a large portion of the North American continent began melting and retreating toward the north, a sudden cooling period known as the Younger Dryas reversed the warming process and caused glaciers to expand again. Even though this cooling period lasted only for 1,300 years, a blink of an eye in geologic timeframes, it witnessed the disappearance of an entire fauna of large mammals. read more