66 million to 23 million years ago, the Neogene 23 million to 2.6 million years ago), and the Quaternary 2.6 million years ago to the present.
The Cenozoic Era, which began about 65 million years ago and continues into the present, is the third documented era in the history of Earth.Quaternary Period 2.6 million years ago to the present), consisting the Pleistocene and Holocene epochs.The Cenozoic Era, which began about 65 million years ago and continues into the present, is the third documented era in the history of Earth. The current locations of the continents and their modern-day inhabitants, including humans, can be traced to this period
The Oligocene Epoch, right smack in the middle of the Tertiary Period (and end of the Paleogene), lasted from about 33.9 to 23 million years ago.* Although it lasted a "short" 11 million years, a number of major changes occurred during this time. These changes include the appearance of the first elephants with trunks, early horses, and the appearance of many grasses — plants that would produce extensive grasslands in the following epoch, the Miocene.
- The Pliocene, 5.3 to 2.6 million years ago,* was a time of global cooling after the warmer Miocene. The cooling and drying of the global environment may have contributed to the enormous spread of grasslands and savannas during this time. The change in vegetation undoubtedly was a major factor in the rise of long-legged grazers who came to live in these areas.
The Holocene Epoch is the current period of geologic time. Another term that is sometimes used is the Anthropocene Epoch, because its primary characteristic is the global changes caused by human activity. This term can be misleading, though; modern humans were already well established long before the epoch began. The Holocene Epoch began 12,000 to 11,500 years ago at the close of the Paleolithic Ice Age and continues through today.