Mesozoic is an adjective used to describe the era or a set of rocks dating from roughly 252 to 66 million years ago, between the Paleozoic and Cenozoic. It often appears in discussions of biology, geology, and paleontology to denote characteristics, formations, or events from that era. The term also informs classifications of periods, life-forms, and environments typical of the Mesozoic world.
Full pronunciation guide