The Ice Age odyssey begins in the 'land of the sabre-tooth' - North America, a continent that was half covered by ice that was up to two miles thick. Yet this frozen land also boasts the most impressive cast of Ice Age giants in the world.High in a cave in the Grand Canyon, Alice discovers the mummified excrement of the loveable, grizzly bear-sized Shasta ground sloth. Lying in the sands of Arizona are the shelled remains of a glyptodon, surely the weirdest mammal that ever lived. On the coastal plains of California, Alice encounters the vast Columbian mammoth, an animal far larger than any elephant today.These leviathans all have one thing in common: they were stalked by the meanest big cat that ever prowled the earth, armed with seven-inch teeth and hunting in packs - Smilodon fatalis, the sabre-toothed cat.