The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period and spans from 2.588 ± 0.005 million years ago to the present. The relatively short period is characterized by a series of glaciations, the appearance and expansion of anatomically modern humans, and their continuing impact on the natural world. The Quaternary includes two geologic epochs: the Pleistocene and Holocene. A proposed but as of yet informal third epoch, the Anthropocene, has also gained credence as the time in which humans began to profoundly affect and change the global environment, although its start date is still disputed.
Read more about Quaternary: Quaternary Glaciation