The Mesozoic ERA, also known as the Age of Reptiles, was an ERA in Earth's history that lasted from about 252 million to 66 million years ago. It is divided into three periods: Triassic, Jurassic, and Cretaceous. During this time, the continents were still connected in the supercontinent Pangaea, and the climate was warm and humid. The Mesozoic ERA saw the rise of the dinosaurs, the first birds, and the first flowering plants. It was also a time of great geological activity, with the formation of mountain ranges and the breakup of Pangaea.