Mary Allen
Introduction: What is the “Age of Mammals”?
The “Age of Mammals,” also known as the Cenozoic Era, is a geological time period that began after the extinction of the dinosaurs and lasted from around 66 million years ago to the present day. During this era, mammals became the dominant group of animals on Earth, with a wide range of species evolving and diversifying to fill ecological niches in various habitats around the world.
This era is characterized by significant changes in climate, geography, and biodiversity, as well as the emergence and evolution of many iconic mammalian groups, such as primates, carnivores, ungulates, and rodents. The “Age of Mammals” is therefore a crucial period in the history of life on Earth, and understanding its key events and processes is essential for comprehending the origins and development of the modern biosphere.
The era of dinosaurs and the rise of mammals
Before the “Age of Mammals,” the Mesozoic Era was dominated by the dinosaurs, which ruled the planet for over 180 million years. However, towards the end of the Cretaceous period, around 66 million years ago, a catastrophic event occurred that caused the extinction of the non-avian dinosaurs and many other groups of organisms.
This allowed the mammals, which had been living in the shadow of the dinosaurs for millions of years, to diversify and expand into new ecological roles and habitats. The earliest mammals were small, shrew-like creatures that lived in the shadows of the dinosaurs, but over time they evolved into a vast array of forms, from tiny insectivores to massive herbivores and predators. This process of diversification and radiation is known as the “adaptive radiation” of mammals, and it is one of the hallmarks of the “Age of Mammals.”