In the dry season of the Jurassic year, the sun beats down relentlessly and the ground cracks into dust. A herd of Apatosaurus , each nearly 80 feel long and weighing 30 tons, thumps across the fern prairie seeking relief at the water hole. Giants like these rule the flat plains in what is now Colorado. These massive dinosaurs rely on their size and bulk to protect themselves from smaller, nimbler predators. Step back in time 150 million years to this prehistoric environment and follow several dinosaur species through a typical day, as they feed, hunt, and try to survive.