History of Earth the late Paleozoic. The Mesozoic ("middle life") era lasted from 251 Ma to Ma. It is subdivided into the Triassic, Jurassic, and Cretaceous periods. The era began with the Permian–Triassic extinction event, the most severe extinction event in the fossil record; 95% of the species on Earth died out. It ended with the Cretaceous–Paleogene extinction event that wiped out the dinosaurs.. The Cenozoic ("new life") era began at Ma, and is subdivided into the Paleogene, Neogene, and Quaternary periods. These three periods are further split into seven sub-divisions, with the Paleogene composed of The Paleocene, Eocene, and Oligocene, the Neogene
Triassic dry, with deserts spanning much of Pangaea's interior. However, the climate shifted and became more humid as Pangaea began to drift apart. The end of the period was marked by yet another major mass extinction, the Triassic–Jurassic extinction event, that wiped out many groups and allowed dinosaurs to assume dominance in the Jurassic. The Triassic was named in 1834 by Friedrich von Alberti, after the three distinct rock layers ("tri" meaning "three") that are found throughout Germany and northwestern Europe—red beds, capped by marine limestone, followed by a series of terrestrial mud- and sandstones—called the "Trias". The Triassic is usually