America's Deep South is today a haven for the manatees, alligators and waterbirds which abound in its clear, turquoise springs. But when the Ice Age gripped much of the continent, the south was a warm paradise for the earliest human hunters as well as warmth loving wildlife. Tapirs and capybaras grazed in the swamps, dwarfed by the giant ground sloths which towered above them. Sabre-tooth cats came to face to face with skunks and jaguars stalked armoured glyptodonts.

• Jack Fortune