The climate during this time was hot and dry because of the high volcanic activity and lack of rain. The volcanic activity caused the plates to shift causing the different continents. During the late Triassic era over 220 million years ago the first mammals were born. For example the therapsids are tiger like prehistoric mammals. The Triassic era ended with a mass extinction accompanied by volcanic eruptions. The pangea supercontinent was broken apart. 35% of plants and animals died out. All animals went extinct except mammals.
The Jurassic period was the most evolved period during the Mesozoic era. Their were more dinosaurs and different species then Triassic. In the beginning of the Jurassic time it was most;y hot and dry. When the Pangaea started to break apart there were vast floods flooding different. There were two dinosaur groups during this time. The giant sauropods like the Brontosaurus. Then there were the carnivorous ones the Carnivorous Theropods. There was minor extinction during this time. Mostly the sauropod s were the dinosaurs that died out.
The Cretaceous was the last period during the Mesozoic era. This period was the heyday of the dinosaurs. Dinosaurs like the Tyrannosaurus Rex and the Triceratops. The area of this time was covered in forests. Seasonal changes were coming. The sea level was normal until the mid-cretaceous time. That was a time of high tectonic plate activity and volcanic activity. Mountain ranges were form like then California's sierra Nevada's. There was a mass extinction. All dinosaurs were executed except for the birds. It is thought that the, dinosaurs were hit by an asteroid, but there are other theories that say it was a volcanic eruption, a continental drift due to climate change and infection from disease.
