The Cenozoic Era is the most recent geologic era, which began about 66 million years ago and continues to the present day. It is also known as the "Age of Mammals" because of the diversification and dominance of mammals during this time.
The Cenozoic Era is divided into three periods: the Paleogene, Neogene, and Quaternary. The Paleogene period, which lasted from about 66 to 23 million years ago, saw the recovery of life after the mass extinction event that wiped out the dinosaurs at the end of the Cretaceous period. During this time, mammals diversified and evolved into many different forms, including the first primates, horses, and whales.
The Neogene period, which lasted from about 23 to 2.6 million years ago, saw the continued diversification of mammals, including the emergence of modern groups such as cats, dogs, and rodents. The climate also cooled during this time, leading to the development of grasslands and the evolution of grazing mammals such as antelopes and bison.
The Quaternary period, which began about 2.6 million years ago and continues to the present day, is characterized by a series of ice ages and interglacial periods. During this time, humans evolved and spread across the globe, developing agriculture, technology, and complex societies.
The Cenozoic Era has seen the evolution and diversification of many modern forms of life, including primates, carnivores, ungulates, and rodents. It has also witnessed the impact of human activities on the environment, including climate change, habitat destruction, and species extinctions.