Pliocene Era

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Pliocene Era
5.3 1.8 MYA
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The Pliocene is often subdivided into two roughly
equal parts, the Early Pliocene (Zanclean) and
Late Pliocene (PiacenzianGelasian)
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• The Pliocene is the fifth epoch of the Cenozoic
  era
• The epoch started around 5 million years ago and
  lasted almost 3.5 million years
• During the Pliocene the first bipedal ancestors
  of humans are known to have evolved
• Dramatic cooling and a drop in sea level impacted
  both marine and terrestrial life

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Earth Development

• Continents had taken up their present-day
  positions
• India collided with Asia and gave rise to the
  Himalayan Mountains
• The Mediterranean was undergoing repeated drying
  and refilling
• Repeated flooding of the Mediterranean caused
  changes in climate and species extinctions
• The Panamanian land bridge formed due to the
  movement of the South American continental plate
  into North America
• This land bridge blocked the passage of water
  between the Atlantic and Pacific oceans and
  allowed land species to migrate between the two
  continents

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Appearance of land during the Pliocene
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Mass Extinction

• The interaction and competition for resources
  resulted in the extinction of numerous South
  American species.
• The accumulation of ice at the poles was a major
  impact which caused the extinction of most
  species living there

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Mammals of Pliocene
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Climate

• Climates became cooler and drier
• The land and ocean cooled
• The beginning of the large ice caps
• The Himalayan uplift triggering a great global
  cooling
• The cooling and drying of the environment may
  have contributed to the enormous spread of
  grasslands and savannas

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Dominant Species

• The plants of the Pliocene does not differ much
  from that of the Miocene
• Grasslands replaced forests
• Cattle, sheep, antelopes, gazelles, and other
  bovids reached their peak.
• North American mammals included horses, camels,
  deer, pronghoms, mastodonts, beavers, weasels,
  dogs, and saber-toothed cats. 
• Rhinoceroses and protoceratids died out in North
  America.
• The one-toed horse appears for the first time.

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• The large-brained australopithecine, Homo
  habilis, continued on into the Early Pleistocene
• It was the common ancestor of both Neanderthal
  and modern man

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Theories

• Not everything in the Pliocene can be explained
  by temperature reductions associated with the Ice
  Age
• The temperature in the Caribbean was constant and
  may actually have increased slightly
• Changes in ocean circulation had very important
  effects
• Evolution happens in bursts

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