The fossils of the newly identified Vulpes qiuzhudingi, which lived 3.60 to 5.08 million years ago, in the Pliocene period, are the oldest arctic fox remains ever found. That could make them the earliest known ancestor of today's arctic fox (Alopex lagopus), which ranges throughout the northern poles. (Also see "Arctic Foxes Put Eggs in 'Cold Storage' for Lean Times.")
The discovery also supports the "out of Tibet" theory, which argues that the plateau acted as a "third Pole" where cold-adapted predators lived until they migrated to new lands at the beginning of the Ice Age.
Between 2006 and 2012, scientists unearthed three jaw fossils of the ancient predator while digging in Tibet's Zanda Basin and Kunlun Mountains.
In 2010, the team found an exemplar fossil of a jaw still studded with teeth. "I first uncovered part of the lower molar, and immediately I knew it was some kind of a dog," said study co-author Zhijie Jack Tseng, a paleobiologist at the American Museum of Natural History in New York City.