Jurassic Period

201–145 Million Years Ago

The Jurassic Period was the golden age of dinosaurs. Sauropods grew to staggering sizes, theropods diversified into efficient predators, and the first birds (Archaeopteryx) evolved from small feathered dinosaurs. Pangaea continued to break apart, opening the Atlantic Ocean. Warm seas supported abundant marine life including ammonites, belemnites, and marine reptiles.