Mustela putorius
The earliest true polecat was "Mustela stromeri", which appeared during the late Villafranchian. It was considerably smaller than the present form, thus indicating polecats evolved at a relatively late period. The oldest modern polecat fossils occur in Germany, Britain and France, and date back to the Middle Pleistocene. The European polecat's closest relatives are the steppe polecat and black-footed ferret, with which it is thought to have shared "Mustela stromeri" as a common ancestor. The European polecat is, however, not as maximally adapted in the direction of carnivory as the steppe polecat, being less specialised in skull structure and dentition. The European polecat likely diverged from the steppe polecat 1.5 million years ago based on IRBP, though cytochrome b transversions indicate a younger date of 430,000 years. It is also closely related to the European mink, with which it can hybridise.