North American Megafauna Extinction: Climate, Humans, and Catastrophe The end of the Pleistocene epoch, roughly 12,000 years ago, marked more than the passing of an ice age—it was the collapse of an entire ecological world. Late Pleistocene North America supported a diverse guild of large-bodied animals, clinically defined as megafauna (species exceeding 44 kg / 97 lbs). Among them were the proboscideans—Woolly Mammoths (Mammuthus) and American Mastodons (Mammut); apex predators such as the Sabe

Late Pleistocene Megafaunal Extinctions