Oligocene Epoch

The Oligocene Epoch, occurring roughly 34 to 23 million years ago, was a period of significant global change. It saw the cooling of Earth's climate after the warm Paleocene and Eocene periods, leading to the development of more open forests and grasslands. During this time, many modern mammal groups, such as early whales, grazing mammals, and ancestors of cats and dogs, continued to evolve. It also marked important changes in ocean currents and the formation of some continents’ current shapes. Overall, the Oligocene was a key time for Earth's biological diversity and climate transition toward the cooler, more connected planet we see today.