> Which geological era do we live in today?And the answer: Cenozoic. Image courtesy: Public Domain.Dinosaurs lived in the Mesozoic era, which endedabout 66 million years ago when it's believed an asteroid hit the earth. That'sthe time when the Cenozoic era began and continues to today. This is sometimesreferred to as the Age of Mammals, because after the asteroid, the extinction ofmany animals allowed mammals to greatly diversify.The Cenozoic era can be divided into 3 periods: * Paleogene Period (65-23 million years ago), which consists of the Paleocene, Eocene and Oligocene epochs, * Neogene Period (23-2.6 million years ago), which includes the Miocene and Pliocene epochs, * and Quaternary Period (2.6 million years ago to the present), consisting the Pleistocene and Holocene epochs.Recent scientists have made the argument that we have since moved into a newepoch: the Anthropocene. The argument stems from the notion of humanity'sirrevocable change following the nuclear proliferation of the 1950s and theimpact of pollution on the climate. As a result, some scientists argue that thechanges have set our Earth in a new direction altogether.At the start of the Cenozoic era, our Earth scarcely resembled how it appearstoday. After the disappearance of the dinosaurs, there were suddenly many emptyplaces on Earth where animals could live. Mammals, which were small, mouse-likeanimals at the beginning of the Cenozoic, quickly spread out, diversified, andgrew in size. Soon, the plains and forests of Earth were occupied by giantrhinos and elephants, lions and saber-tooth cats, horses and deer. The skiesfilled with bats and birds, and the seas filled with whales and porpoises, aswell as with fish and octopi. There have been mass extinctions during theCenozoic as there were during the Mesozoic and Paleozoic, but not nearly as manyanimals and plants have disappeared.Only within the last 2 million years has humanity entered the frame ofexistence. In the last 10,000, humanity has spread across the Earth to becomethe most prominent species on the planet. Now, as we seek to sustain our way oflife, we must ask ourselves how we may preserve our planet and resources for themillennia to come.