Watch Special The Mystery of Earth's Disappearing Giants 21m 29s We investigate a mystery. Millennia ago, while much of the Earth was covered in ice, enormous animals lived on every continent except Antarctica. Species like ground sloths, mammoths, gomphotheres, sabertooth cats, even wombats the size of cars! Today, Africa is the only continent where these megafaunas still exist. Why? What happened to the rest of Earth’s giants?