The Miocene Epoch 23 to 5 mya At right is pictured (in front), Chalicotherium, a Miocene mammal from Kazakhstan. Chalicotherium was an unusual odd-toed hoofed mammal, or perissodactyl. Both the perissodactyls and artiodactyls underwent a period of rapid evolution during the Miocene. The Miocene was a time of warmer global climates than those in the preceeding Oligocene, or the following Pliocene.