Around 12,000 years ago, humans arrived in North America. At the same time, after millions of years of relative stability—again, even through wild shifts in climate—North America lost a staggering array of megafauna. The continent was home to a suite of animals far surpassing in grandeur that found on any modern African savanna. It lost its four species of mammoths, its elephant-like gomphotheres, and its giant ground sloths—some towering 15 feet tall on their hind legs. It lost its giant armadillos weighing more than a ton; beavers the size of bears; bears, like arctodus, that were far larger
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