Woolly Mammoth Mammuthus primigenius, a relative of elephants, roamed the earth from around 5 million years ago until approximately 4,000 years ago. Leading contributors to their extinction include the end of the ice age, drastically limiting their available food sources, and being hunted by man. They ate a specialty diet of grasses and sedges, using their tusks to dig through snow to find frozen grass in the wintry tundra. They had long, curved tusks and four molars, which were replaced six times during the lifetime of an individual.