Arctic fox

The Pliocene Tibetan fox (Vulpes qiuzhudingi) is considered the ancestor of this species.

An excerpt from the article 22 facts about Arctic fox
The Tibetan highlands experienced Pliocene (5 to 3,6 million years ago) climate conditions similar to those of the tundra and harbored cold-adapted mammals that spread across North America and Eurasia during the Pleistocene era (2,6 million – 11,7 thousand years ago).