How The Life Begin

Further information:  Evolution of mammal s The first true mammals evolved in the shadows of dinosaurs and other large archosaurs that filled the world by the late Triassic. The first mammals were very small, and were probably nocturnal to escape predation. Mammal diversification truly began only after the Cretaceous-Paleogene extinction event.By the early Paleocene the earth recovered from the extinction, and mammalian diversity increased. Creatures like  Ambulocetus  took to the oceans to eventually evolve into whales, whereas some creatures, like primates, took to the trees. This all changed during the mid to late Eocene when the circum-Antarctic current formed between Antarctica and Australia which disrupted weather patterns on a global scale. Grassless  savannas  began to predominate much of the landscape, and mammals such as  Andrewsarchus  rose up to become the largest known terrestrial predatory mammal ever,and  early whales ...