Mesozoic Era

The Mesozoic Era is a significant period in Earth's geological history, stretching from approximately 252 to 66 million years ago. It comprises three distinct periods: the Triassic, Jurassic, and Cretaceous periods. The Mesozoic is marked by profound biological and geological changes, earning it the moniker "Age of the Dinosaurs." This era followed the catastrophic Permian–Triassic extinction event, which was the largest mass extinction in Earth's history.

Geological Features

During the Mesozoic Era, the supercontinent Pangaea began to break apart, leading to the formation of the modern continents. This tectonic activity created new ocean basins and mountain ranges, which significantly impacted the global climate. The era is characterized by a hot, greenhouse climate, with relatively high levels of atmospheric carbon dioxide.

Flora and Fauna

Dominance of Reptiles

The Mesozoic is best known for the dominance of archosaurian reptiles such as the dinosaurs. Dinosaurs were the dominant terrestrial vertebrates, spreading across both hemispheres. The era also saw the rise of marine reptiles like mosasaurs and plesiosaurs, as well as flying reptiles known as pterosaurs.

Evolution of Mammals

The first mammals appeared during the Mesozoic, although they remained relatively small, generally less than 15 kg (33 lb), until the subsequent Cenozoic Era, which followed the Mesozoic.

Plant Life

The Mesozoic was initially dominated by gymnosperms such as cycads, ginkgoaceae, and araucariaceae conifers. However, the Early Cretaceous witnessed the emergence and rapid diversification of flowering plants, which would eventually overshadow other plant groups as the dominant form of flora.

Major Events

The Mesozoic Marine Revolution

During the Mesozoic, the Mesozoic Marine Revolution occurred, marked by an increase in shell-crushing (durophagous) and boring predation in shallow-sea environments. This revolution led to significant evolutionary pressures on marine life, encouraging the development of defensive adaptations like harder shells and more burrowing behaviors.

Cretaceous–Paleogene Extinction Event

The Mesozoic Era came to a dramatic close approximately 66 million years ago with the Cretaceous–Paleogene extinction event. This devastating event is best known for causing the extinction of the non-avian dinosaurs, alongside the pterosaurs, mosasaurs, and other species. It marked the end of the Mesozoic and ushered in the Cenozoic Era.