The Cenozoic Era is the geological time period we're living in right now. It began 66 million years ago when the dinosaurs went extinct and continues to the present day. Scientists divide Earth's immense history into eras, and the Cenozoic is the most recent one.

This era saw the rise of mammals, birds, and flowering plants that dominate our world today. After a massive asteroid wiped out the dinosaurs, mammals evolved from small, shrew-like creatures into the incredible diversity we see now: whales, elephants, bats, horses, and eventually humans. The Cenozoic is sometimes called the “Age of Mammals” for this reason.

During the Cenozoic, continents drifted into their current positions, the Himalayan mountains formed from colliding landmasses, and ice ages came and went. The climate gradually cooled over millions of years, creating the polar ice caps we have today.

If you imagine Earth's entire 4.6 billion-year history compressed into a single year, the Cenozoic Era would be just the last few days of December. Yet in that relatively short time, the world transformed from a dinosaur-dominated planet into one where mammals, including humans, became the largest land animals.