Taking up where the Walking with Dinosaurs documentary ended, Prehistoric Beasts will awe you with up-close and personal looks at species that became extinct a few thousand years ago -- just a blink of an eye on history's time line. It's the dawn of the age of mammals when creatures such as the smilodon, the giant ground sloth and the saber-toothed tiger roamed the savannahs -- as did man in his earliest incarnations.