The Mesozoic Era is made up of three eras. The Cretaceous Period, The Jurassic Period, and The Triassic Period.
Reptiles were so successful in the Mesozoic Era, it was often called The Age Of The Reptiles.
Dinosaurs became very common on land. Other kinds of reptile evoked to live in water or in the air. The first dinosaurs appeared 225 million year ago in the Triassic Period. Mammals also evolved in the Triassic Period but most mammals that evolved were about as small as a mouse.
In the Cretaceous Period mammals began to take over the dinosaurs. Birds began to replace flying reptiles and flowering plants began to evolve in this period.
Mass extinction happened at the end of the Cretaceous Period. When an asteroid came hurtling torward Earth. When it struck it wiped all of the dinosaurs out.