What three periods make up the mesozoic era?

The Mesozoic Era is divided into three periods: the Triassic, Jurassic, and Cretaceous. The Triassic period, which lasted from about 252 to 201 million years ago, saw the rise of the first dinosaurs and mammals. The Jurassic period, from approximately 201 to 145 million years ago, is known for the dominance of dinosaurs and the appearance of the first birds. Finally, the Cretaceous period, lasting from about 145 to 66 million years ago, featured diverse dinosaur species and ended with a mass extinction event that led to their demise.