Second of the Earth's three major geologic eras and the interval during which the continental landmasses as known today were separated from the supercontinents Laurasia and Gondwana by continental drift. It lasted from 248 to 65 million years ago and includes the Triassic, Jurassic, and Cretaceous periods. The Mesozoic saw the evolution of widely diversified and advanced flora and fauna, quite different from those that had developed earlier during the Paleozoic Era or that would develop later during the Cenozoic Era