In this four-part documentary from Discovery Channel, the natural calamities that transformed life on Earth over the course of billions of years are examined for their effects on the world's prehistoric beasts. See how once-dominant species were rendered extinct while new and evolved creatures took their place─from single-celled beings to the most gigantic of dinosaurs─and learn how this journey through global catastrophe gave rise to humanity. 3 2/3 hrs. total. Widescreen (Enhanced); Soundtrack: English Dolby Digital stereo; Subtitles: English (SDH); bonus footage.