- "The Ice Age" redirects here. For other uses, see Ice Age (disambiguation).
The Pleistocene stage or epoch was a long period of time. It stretched from 2.6 million years ago to 11,700 years ago. The Pleistocene followed the Pliocene. It is the first stage of the Quaternary period, and is followed by the present Holocene.
The Pleistocene was one long ice age: cold glacial periods with shorter, warmer, interglacials. Ice ages are when the world becomes much colder for a long time. Much of the world we know was covered by ice: North America down to and past the Great Lakes; all of northern Russia, and Europe; England down to the Thames.
Many animals that lived then have become extinct. Climate change and hunting by humans were responsible. Many of the mammals were larger and hairier versions of animals that live now. Glyptodon was something like a giant armadillo, and mammoths were hairy elephants.
Ancient human species lived during the Pleistocene. In Europe and Asia the large-brained Neanderthal Man (Homo neanderthalensis) lived until about 30,000 years ago. Modern man did not descend from Neanderthals, but originated in Africa from another branch of the genus.
References[change | edit source]
- International Commission on Stratigraphy (ICS). ICS geologic time scale
- Martin P.S. and Klein R.G. eds 1984. Quaternary extinctions: a prehistoric revolution. Arizona, Tucson AZ.
- Klein, Richard G. 2009. The human career: human biological and cultural origins. 3rd ed, Chicago.
|Precambrian (4.567 gya – 541 mya)|
|In the left column are Eons, bold are Eras, not bold are Periods. gya = billion years ago, mya = million years ago|
|Hadean (4.567 gya – 4 gya)|
|Archaean (4 gya – 2.5 gya)||Eoarchaean (4 gya – 3.6 gya)|
|Proterozoic (4 gya – 2.5 gya)||Palaeoproterozoic (2.5 gya – 1.6 gya) Siderian (2.5 gya – 2.3 gya) Rhyacian (2.3 gya – 2.05 gya) Orosirian (2.05 gya – 1.8 gya) Statherian (1.8 gya – 1.6 gya)|
|Phanerozoic (541 mya – today)|
|In the left column are Eras, bold are Periods, not bold or italics are Epochs, Italics are stages. kya = thousand years ago, mya = million years ago|
|Palaeozoic (541 mya – 252.17 mya)||Cambrian (541 mya – 485.4 mya)|
|Mesozoic (252.17 mya – 66.0 mya)||Triassic (252.17 mya – 201.3 mya) Lower Triassic (252.17 mya – 247.2 mya) Middle Triassic (247.2 mya – 237 mya) Upper Triassic (237 mya – 201.3 mya)|
|Cainozoic (66.0 mya – today)||Palaeogene (66.0 mya – 23.03 mya) Palaeocene (66.0 mya – 56 mya) Eocene (56 mya - 33.9 mya) Oligocene (33.9 mya – 23.03 mya)|
|Source||International Chronostratigraphic Chart 2013. International Commission on Stratigraphy, retrieved 8 April 2013. Divisions of geologic time – major chronostratigraphic and geochronologic units USGS, retrieved 8 April 2013.|