The second Era, the Mesozoic Era is known as the age of reptiles. It is classified into three peroids: 1) triassic, 2) jurassic and 3) cretaceous.
1) Triassic (253-200 mya): Emergence of egg-laying mammals, forests of conifers, cycads and other Gymnosperm.
2) Jurassic (200-144 mya): Dominance of Dinosaurs, primitive birds, Gymnosperm and evolution of Marsupials.
3) Cretaceous (144-67 mya): Extinction of Dinosaurs, primitive birds and emergence of first modern birds, Angiosperms.