The Mesozoic Era (251.9 to 66.0 million years ago) encompasses the entire evolutionary rise, diversification, and extinction of non-avian dinosaurs. Stratigraphically partitioned into three major systems—the Triassic, Jurassic, and Cretaceous—each period witnessed monumental continental drift, climatic shifts, and faunal turnovers.
The dawn of the Mesozoic Era. Dinosaurs first emerged in the Late Triassic following the catastrophic Permian-Triassic extinction event, initially occupying modest niches alongside crurotarsan archosaurs.
Marked by lush greenhouse climates, the breakup of Pangaea, and the evolutionary explosion of sauropods, plated stegosaurs, and apex megalosauroid and allosauroid theropods.
The longest and final period of the Mesozoic Era, characterized by the rise of flowering plants, ceratopsians, hadrosaurs, tyrannosaurids, and concluding with the Chicxulub asteroid impact.