The Cenozoic era is the most recent geological time period, spanning from about 66 million years ago to the present. It follows the Mesozoic era and is characterized by significant changes in climate, geography, and the evolution of mammals and birds. This era is divided into three periods: the Paleogene, Neogene, and Quaternary. During the Cenozoic, the continents moved to their current positions, and the climate became cooler and drier. This era saw the rise of many modern species, including humans, and the extinction of large prehistoric animals like the woolly mammoth. The Cenozoic is often referred to as the "Age of Mammals" due to the dominance of mammals in various ecosystems.