The Mesozoic Era happened right after the Permian extinction. The periods that make up the Mesozoic Era are the Triassic, Jurassic, and Cretaceous periods. The Mesozoic Era was about 251 million years ago.
The Mesozoic Era was mostly filled with Reptiles and Dinosaurs, but their were some mammals that evolved during that time to. That's why they called the Mesozoic Era, the Age of Reptiles.
Some animals survived the Permian Extinction. For example fish, insects, reptiles, and cone-bearing plants. The Triassic Period were when the dinosaurs came, and the reptiles were very popular. Mammals also appeared. But the mammals were very small.
This is when dinosaurs became very popular on land. That is when scientists found new reptile species such as the Archaeopteryx, and the Dimorphidon.
Dinosaurs and reptiles were still widespread. This is when birds replaced flying reptiles. Flowering plants first evolved in the Cretaceous period. These flowering plants produced seeds.
Another Mass Extinction
At the end of the Cretaceous period there was a mass extinction. It made all the dinosaurs go extinct, and many different animals died out. Scientists think an asteroid struck earth creating the mass extinction.