The Jurassic period was a time of the dinosaurs that occurred between 201 and 145 million years ago. It was the second period of the Mesozoic era, which is also known as the Age of Reptiles. During this time, many species of dinosaurs evolved and flourished, including the iconic Tyrannosaurus Rex. The Jurassic period was also marked by the emergence of the first birds and the evolution of flowering plants.