Dogs have been a loyal companion to mankind for more than 30,000 years, it has been revealed.
Scientists believe that two, 33,000-year-old skulls unearthed in separate digs in Siberia and Belgium show dogs were domesticated long before any other animal, including sheep, cows or goats.
The skulls had shorter snouts and wider jaws than undomesticated animals like wolves, which use their longer snouts and narrower jaws to help them hunt, according to researchers from the University of Arizona
This means the dogs had been kept for protection and companionship by our ancient ancestors - just like they are today.
The researchers believe dogs could have been the first species of animals to be domesticated by humans, before farm animals were bred for their meat and skins. This offers an explanation for why breeds like pugs and huskies look so different, despite being the same species.