25 million years ago, Late Oligocene (Mongolia) Filming location: Mexico, ArizonaThe third episode takes place during the late Oligocene, in Mongolia, where there were seasonal rains followed by a long drought. It tells the story of a mother Paraceratherium (identified as Indricothere), a massive hornless rhinoceros that was the largest land mammal to have ever lived. The episode first shows the mother Paraceratherium giving birth, and then tending to the male calf as it matures. A few minutes after giving birth, the mother defends the helpless calf from several Hyaenodon. Also, the mother's old calf tries to come back, but is chased away. It gives a snapshot into the future of the calf. The mother raises her calf for three years, but eventually chases him away after she mates with another male. The episode then chronicles the young Paraceratherium travels until it reaches adulthood, including encounters with the Cynodictis (identified as bear dog), and the large aggressive Entelodon.Animals: Paraceratherium (identified as Indricothere) · Hyaenodon · Entelodon (identified as Entelodont) · Chalicotherium (identified as Chalicothere) · Bear dog (Cynodictis)