The Cenozoic era is an era that encompasses the past 65 million years of Earth history.
During this era mammals replaced reptiles as the dominant land animals. It is often called the age of mammals because land mammals came to dominate land life. Additionally, the development of flowering plants during this period influenced the evolution of birds and mammals.
The mammals were warm-blooded, and they could survive in cold regions and search for food during any season or time of day, they also adapted insulating body hair and more efficient lungs and hearts.
