Description: Arizona, USA- 220 million years B.C. In the blazing Pangaean deserts of the Late Triassic, the first dinosaurs appear. The episode chronicles the fate of a predatory Postosuchus driven from her territory, a herd of Placerias struggling to survive the drought and a couple of cynodonts- early ancestors to modern mammals- trying to protect their young from opportunistic Coelophysis. The dinosaurs have not yet grown into the dominant animals of Earth's ecosystems, but the giant Plateosaurus offers a glimpse of things to come.