When was the Jurassic period?
The Jurassic Period (200–145 million years ago) began after the mass extinction that ended the Triassic Period. This mass extinction allowed dinosaurs to flourish in the Jurassic Period, which is called the golden age of dinosaurs. It opened up many new niches for dinosaurs to exploit. Also during the Jurassic, the earliest birds evolved from dinosaur ancestors. All of the major groups of mammals evolved, as well, although they were all small in size. Flowering plants appeared for the first time, and new insects evolved to pollinate flowers. The continents continued to move apart, and volcanic activity was especially intense.