S1, E4: This episode journeys back 150 million years to the Jurassic period. This was a time when the first giant killers stalked the earth predators like the fabled Allosaurus. But these giants weren’t confined to the land, recent discoveries have revealed an astonishing new hunter in the oceans, a predator that dwarfs almost all others; Predator X. From the oceans to the land these new giant killers posed the greatest of threats with the smallest advantage tipping the balance between life and death. Predator and prey were locked in a perpetual battle for survival.