The Mesozoic Era

The Mesozoic Era begins at the end of the Permian Period. Mass extinction had eliminated most of the species of life that had existed throughout the Paleozoic Era.

The Continents

At end of the Paleozoic Era the land that would become the continents of Europe and Asia crashed into North America. By the time of the Mesozoic Era Pangea the super continent had formed.

Climate During The Mesozoic Era

The temperatures, both on land and in the ocean, were much higher than during the Paleozoic, and climates were more tropical in nature. Despite this, the seas were lower, leaving different types of land masses for life to deal with. Over all the Mesozoic Era was dryer than in the Paleozoic Era. There were more deserts and less marshland.

Life Recovers From The Permian Extinctions

It took most of the first and second periods of the Mesozoic, the Triassic and the Jurassic periods, for the diversity of species to recover and achieve some balance. While plant species had survived somewhat better than animals over the Permian Extinction, new types of plants developed to survive the changing conditions.

The warmer drier conditions of the Mesozoic required new reproductive methods in plants. Ferns and gymnosperms developed. Their reproductive methods allowed for good protection of the spores or seeds that would have to get through periods of drought before growing into the infant plant.

Marine Life

The survivors of the Permian Extinction had very little competition. Corals, mollusks and fish dominated the life in the oceans. Some Reptiles took to the water to become the first air breathing hunters in the oceans. They took on a variety of forms and rose to the top of the food chain.

The Rise of The Reptiles and Dinosaurs

The dominant land animals at the end of the Permian Period were the Synapsids. This group of animals is characterized by having a single hole on each side of the skull behind the eye. They are sometimes called mammal like reptiles. This group nearly became extinct at the close of the Permian Period.

The animals that developed in the Mesozoic Era needed new body types to survive the extremes of temperature and moisture. Amphibians developed respiratory mechanisms that allowed them to live in or out of the water for extended periods of time. But it was the reptiles that were better adapted to the warmer dryer conditions. They developed thick, leathery skin on both their own bodies and their eggs. The reptiles thrived, dominating the landscape in both size and numbers. They are known as diapsids. Diapsids are characterized by having two openings on each side of the skull behind the eyes.

The dinosaurs evolved from these reptiles and were themselves diapsids. During the Jurassic and Cretaceous Periods the dinosaurs ruled the earth.

Mass Extinction Ends The Mesozoic Era

Another mass extinction occurred at the end of the Cretaceous Period, bringing an end to the dinosaurs and many other species. While this event did not match the Permian Extinction in the destruction of life it was the second most devastating in the fossil record. It is commonly believed that an impact of an asteroid was the cause of this event.