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Pleistocene

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The Pleistocene is the period in Earth’s history that we commonly refer to as the Ice Age . During much of this period, the regions that were located to the north and south of the Earth were totally covered by glaciers approximately one kilometer thick. It is important to recognize that the Pleistocene was a series of actual glaciations, separated by relatively short interglacial periods . This period began 2.6 million years ago and lasted until the end of the glaciation.

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What is the Pleistocene?

Also called the Ice Age , it is the first part of the Cenozoic Quaternary and covers the time of the ice ages . Its end coincides with the end of the Palaeolithic when the continents were already in their current positions.

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  • What happened in the Pleistocene
  • Pleistocene characteristics
  • Pleistocene periods
  • Weather
  • Pleistocene flora
  • Fauna

What happened in the Pleistocene

During this stage the earth was cooled , which had a great effect on its animal life ; the different types of animals, or ecological populations, were severely altered and even some of them were completely eliminated . Some of these species became extinct, and new ones were born at the same time. As the ice sheets accumulated in greater quantity, sea levels fell. Under the sea began to emerge bridges land , the most famous of which was the land bridge Bering and the land bridge between America of the North and America of the South and because of this, a wave of animal migration began to the continents.

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Pleistocene characteristics

The main characteristics of the Pleistocene are mentioned below:

  • The continents were already in the places they occupy today.
  • The climate was a repetition of glacial cycles .
  • It is believed that about 30% of the planet was covered by ice .
  • The oceans dropped in level, creating land bridges in previously isolated areas.
  • There was more drought and, in addition, a greater degree of scarcity in the amount of rain .
  • There was very little evaporation from the oceans and lakes.
  • There was the extinction of some types of animals such as the mammoth and mastodons.

Pleistocene periods

The Pleistocene periods were as follows:

  • Gelasian : this period is considered to be a geological age that begins approximately 2,588 million years ago and ends 1,806 years ago.
  • Calabrian : it is the second age of the Pleistocene and happened between approximately 1,806 and 781 million years ago.
  • Ionian : it is between 0.781 and 0.126 million years old and its limit seems to coincide with the Brunhes-Matuyama magnetic inversion.
  • Tarantian : it is the most recent age and precedes the Holocene epoch.

Weather

The weather was extremely cold and layers of ice were covering all Antarctica , large parts of Europe , America of North and South America, and small areas in Asia . In North America they spread over Greenland and Canada and parts of the northern United States . The remnants of Ice Age glaciers can still be seen in some parts of the world, including Greenland and Antarctica. All this was known by the name of glaciations . 

Glaciations

The glaciations was the name that was used to designate the set of glaciers or cold phases that were interspersed with slightly warmer phases . These cold phases occurred mainly in the northern part of the earth, however, they reached the rest of the world.

Extremely cold temperatures occurred during them, there was no rain and large masses of ice , which on some occasions were even larger than a thousand meters, were in charge of covering the land.

When the temperature rose, these ice masses began a thawing process and the rains began , which caused the seas to rise their levels, and in view of that, most of the coasts of the seas suffered great changes, including the flora and the fauna of these places.

The scientist Milutin Milankovitch , of Yugoslav origin, made several calculations about the solar receptions that were obtained during this phenomenon, and according to his studies there were large variations in the way in which the orbit of the earth is positioned around the sun, they occurred changes in the obliquity in the angle with the orbit of the earth and there was a fluctuation of the axis of the earth.

Pleistocene flora

The flora sought more sheltered areas to develop such as the bottoms of the valleys from which the forests later emerged . With each glaciation changes arose, it also had an advance to become tundra making the species more resistant to the climate. The humidity gave rise to new species such as deciduous tree species and thermophilic plants . In the third period the temperate forest arises , there were prairies and steppes .

Fauna

It was known by the name of megafauna . In the first period, the animals were large carnivores , apes and three-toed horses, there were also mammoths, bears, lynxes, rhinos and cave lions. In the transition period, you could find deer, elephants and rhinoceros with a septum nose.

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