RedOrbit: Today, polar bears and other animals adapted to extremely cold environments inhabit the Arctic tundra. In the past, around 53 to 38 million years ago (the Eocene epoch), the Arctic was not a frozen tundra - rather, it was more like a huge temperate forest with brackish water. This forest was home to a wide variety of wildlife, including the ancestors of modern-day tapirs, hippo-like creatures, crocodiles and giant tortoises. Well-documented terrestrial deposits have given us much of our current knowledge...