The Neogene is a geological period that lasted from about 23 million to 2.6 million years ago. It is divided into two epochs: the Miocene and the Pliocene. During this time, the Earth's climate became cooler and drier, leading to significant changes in ecosystems and the evolution of many species. This period is notable for the rise of mammals and birds, as well as the development of grasslands. The Neogene also saw the formation of major mountain ranges, such as the Himalayas, which influenced global climate patterns and animal migration.