MAMMALS CONQUER THE WORLD

65 million years ago, Dinosaurs and the other giant Reptiles are extinct. No one know why it happens. But, many hypotheses were appeared. But, still no one know the main cause of these reptiles extinction.

Since more than 100 million years before this extinction, the first mammals were born. These mammals were estimated only as big as modern mouse. Almost all of these mammals are nocturnal mammals due the reptiles especially dinosaurs which dominate the world at that time. But, around 65 million years ago, these giant reptiles and dinosaurs suddenly dissappeared from this world. Due to this mass dissappears, Earth become empty from giant reptiles and only mammals and a little of reptiles left.

The mass extinctions of dinosaurs and the other reptiles have allow the survived mammals to develop and grow into various mammals. Even, some of this species developed into winged mammals like bats and some other return to the sea like whale. This fact was known from the anatomy structure of human's hands, whale's fins, and bat's wings which show the homology of mammals anatomy.

Before mammals conquer the world, appeared a kind of giant carnivorous unfyable birds which called Ratit. These birds even have big sharp beak and claws that help these birds to kill it's preys. Even, this giant birds eat "Hyracotherium", the ancestor of Horse. But, the glory of these birds were not long lasting. Not long after they appears, they suddenly extinct.

The glory age of mammals reached at Eocene Era. At this era, mammals reach their most variation of their species. Even at this time, mammals were spread everywhere from continents to the depth of ocean. But, as same as ratit, this glory was not long everlasting. the world climates change, temperature become very low and cause "Ice Age" over the world. This ice age had cause the extinction of some mammals and the survived ones were suffers. But, this climates changes gave advantages to some big mammals like Mammoth and Megaloceros (the largest deer ever known).

But, not long after that, the climates were change once again. the temperature increase and back to normal. But, these two climates changes had suffer not only mammals but almost all of organisms. That's why many mammals become suffer and extinct.