Despite its name, the golden jackal is not closely related to the African black-backed jackal or side-striped jackal, which are part of the genus Lupulella, being instead closer to wolves and coyotes. The ancestor of the golden jackal is believed to be the extinct Arno river dog that lived in Mediterranean Europe 1.9 million years ago. It is described as having been a small, jackal-like canine. Genetic studies indicate that the golden jackal expanded from India around 20,000 years ago, towards the end of the last ice age. The oldest golden jackal fossil, found at the Ksar Akil rock shelter near Beirut, Lebanon, is 7,600 years old. The oldest golden jackal fossils in Europe were found in Greece and are 7,000 years old. There are seven subspecies of the golden jackal. It is capable of producing fertile hybrids with both the gray wolf and the African wolf. Jackal–dog hybrids called Sulimov dogs are in service at the Sheremetyevo Airport near Moscow where they are deployed by the Russian airline Aeroflot for scent-detection.