The Watering Hole. Take a leap back in time to an ancient watering hole, where predators and prey co-exist. This episode transports us to the town of Lourinha, Portugal, where the largest concentration of fossils in Europe exists. We'll show you how this watering hole looked 150 million years ago, during the late Jurassic, where giant sauropods (four-legged herbivores) took a break along migration routes. We see the fight for survival of a young Allosaurus as he battles the giant Dinheirosaurus - a plant-eater with a tail like a 35-foot long bullwhip - and Torvosaurus, a huge predator that competed for prey and territory. We meet the supporting cast of characters who gather near the watering hole, such as Ornitholestes - the "bird-robber" - and Rhamphorhynchus, a flying reptile, not to mention Miragaia, cousin to the well-known Stegosaurus, and Lusotitan, an 82-foot long sauropod. Unlike previously thought, this episode reveals how dinosaurs worked in complex social systems and how the watering hole was the center of that environment where different species lived, and died, together.