The Mesozoic era, meaning “middle life”, is a division of earth’s history spanning from around 252 to 66 million years ago. It is subdivided into the Triassic, Jurassic and Cretaceous periods. The beginning of the Mesozoic is characterised by a long phase of recovery following the end Permian mass extinction. The end of the Mesozoic is marked by the Cretaceous/Paleogene extinction event which wiped out the dinosaurs among other groups.