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 Epoch, 23.03 to 5.3 million years ago,* was a time of warmer global climates than those in the preceeding Oligocene or the following Pliocene and it's notable in that two major ecosystems made their first appearances: kelp forests and grasslands. The expansion of grasslands is correlated to a drying of continental interiors as the global climate first warmed and then cooled.