👉 The Eocene is a geological period in which Earth's climate was relatively stable, with some notable changes occurring between 20 and 65 million years ago. This period saw an increase in volcanic activity and the formation of early mammalian fossils, as well as the first known vertebrates to appear on Earth. The Eocene also saw the emergence of dinosaurs, which were a major contributor to the extinction event that occurred around 65 million years ago.
