33,000 year-old domesticated dog skull found in Siberia

Man's best friend has been around a long time.

(FOX News)- An ancient dog skull found in Siberia and dating back 33,000 years presents some of the oldest known evidence of dog domestication.

When combined with a similar find in Belgium, the two skulls indicate that the domestication of dogs by humans occurred repeatedly throughout early human history at different geographic locations -- rather than at a single domestication event, as previously believed.

"Both the Belgian find and the Siberian find are domesticated species based on morphological characteristics," said Greg Hodgins, a researcher at the University of Arizona's Accelerator Mass Spectrometry Laboratory and co-author of a study reporting the find.

"Essentially, wolves have long thin snouts and their teeth are not crowded, and domestication results in this shortening of the snout and widening of the jaws and crowding of the teeth."

The Altai Mountain skull is extraordinarily well preserved, Hodgins said, enabling scientists to make multiple measurements of the skull, teeth and mandibles that might not be possible on less well-preserved remains. "The argument that it is domesticated is pretty solid," he said. "What's interesting is that it doesn't appear to be an ancestor of modern dogs."

At 33,000 years old, neither the Belgian nor the Siberian domesticated lineages appear to have survived earth's last ice age. Still, they show, just how far back our special relationship with our canine companions goes, Hodgins said.