The Age of Dinosaurs The "Age of Dinosaurs" also known as the Mesozoic Era began over 245 million years ago. It was divided into three periods call the Triassic (245 to 208 million years ago), Jurassic (208 to 145 million years ago), and the Cretaceous (145 to 66 million years ago). The earth during the Mesozoic Era was very different than it is today. The earth was only one continent whereas today it is seven. This huge super-continent was called Pangea. During …showed first 75 words of 728 total…

…showed last 75 words of 728 total…early Triassic period. Roughly 248 million years ago, the Permo-Triassic period extinction occurred. This is the largest extinction known. About 95% of all species and about 60% of the plants died out. This includes many marine animals (like the trilobite). The cause of the Permian extinction might have been from global cooling, volcanic eruptions, or decrease of continental shelf area during the formation of Pangea. This catastrophic extinction opened the doorway to the rise of dinosaurs and mammals.