The prehistoric menagerie didn"t stop with the end of the dinosaurs, as this BBC-produced documentary shows. See how the Age of Mammals gave rise to some of the most unique creatures to ever roam the planet, from 12-foot-tall flightless birds and fierce saber-toothed tigers to snow-dwelling wooly mammoths and giant ground sloths. 5 hrs. total. Standard; Soundtrack: English Dolby Digital stereo; featurettes; storyboards; photo gallery.