We live in the Cenozoic Era. It is known as the “Age of Mammals”. Warm blooded mammals began to evolve after the Cretaceous mass extinction. Body hair as well as complex lungs and hearts allowed them to adapt and thrive in their new environment. Mammals could survive in very cold and hot climates. Mammals were the dominant life-forms during the Cenozoic era. The Cenozoic era consists of two periods: Tertiary and Quaternary.
During the Tertiary period, Pangaea began to break apart and form the continents that exist today. Tectonic plates collide to form the Alps, the Rockies, and Himalayas mountains. The global climate became cooler and drier. Grasslands, cone-bearing trees, and hardwood trees flourish in these new conditions. Glaciers began to form in Antarctica as the temperatures across the world began to decrease and because of its new location.
Many new species of animals evolved in the oceans and on land. Fossil records provide evidence of the first whale, flying squirrels, bats, pigs, and camels. Grass grazing mammals such as the ancestors of horses and cattle, deer, and giant sloths developed flat molars that very useful for chewing. The earliest saber-toothed cat, wolves, and foxes evolved sharp teeth for tearing and cutting their prey.
Fossil evidence indicates that the earliest modern humans, Homo sapiens, emerged during the Quaternary period. Scientists believe modern humans evolved from ancestors in Africa more than 150,000 years ago. Humans and animals are present worldwide because the last ice age produced a land bridge. The land bridge connected North America with Asia. It enabled humans to migrate from one landmass to another. The Quaternary period consists of several epochs. We are living in the Holocene Epoch.