OLIGOCENE

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Paleo-Geography

• Continents continue to drift to present positions
• Africa and India continue to drift into Eurasia
• South America, Antarctica & Australia isolated
• Pacific Ocean shrianks as Atlantic Ocean widens
• Climate warm but begins to cool

Life

• Mammals continue to flourish & grow larger
• Perissodactyls (horses; rhinos) thrive; some huge (right)
• Artiodactyls (camels & ruminants) continue to diversify
• Apes (below right) first appear
• First elephants with trunks appear
• Primitive creodonts slowly replaced by early carnivores
• Grasses spread; deciduous trees & shrubs spread

  
  Mesohippus (left), ancestor   
  of the modern horse, took   advantage of the spreading   grasslands.

   (Image: H.Harder, Palaeos)

Aegyptopithecus (right), the size of a small monkey, lived right at the point where the Hominoids (Apes) first branched off from the Old World monkey group -- and was thus a step
on the road to humans.

(Image: SinDioses, F.Y. Rodríguez)

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