66 Million Years Ago – Present

Cenozoic Era

The Cenozoic Era, the 'Age of Mammals,' encompasses the last 66 million years and continues to the present day. After the extinction of non-avian dinosaurs, mammals underwent a dramatic adaptive radiation, filling ecological niches left vacant. Horses, whales, elephants, primates, and countless other groups evolved and diversified. Grasslands spread across continents, reshaping herbivore evolution and driving the development of running adaptations. The era's later stages were marked by dramatic climate oscillations — the Pleistocene ice ages — that drove cycles of glaciation and profoundly influenced the distribution and evolution of life. The emergence of Homo sapiens in the late Cenozoic has had an unprecedented impact on the biosphere.