Creodonts and ruminant ungulates, a strange carnivorous group, evolve. Oligocene Epoch 34-24 million years ago Tectonic plate movement is still very dynamic. Africa and Europe squeeze together, closing the Tethys Sea and leaving as a remnant the Mediterranean Sea. Volcanism and fragmentation of western North America is associated with the emplacement of major ore deposits. The climate is generally temperate.
Glaciation begins in Antarctica.
Representatives of modern mammals become the dominant vertebrate life form, including horses, pigs, true carnivores, rhinoceroses, elephants, and camels. Oreodonts diversify in North America. Early primates appear in North America, and early apes appear in Egypt. Many archaic mammals become extinct. The world's oceans teem with more diverse vertebrate life.