Experts Date Remains of Oldest Known Dog

ZURICH, Switzerland (Aug. 3) -- Archaeologists say the fragment of a dog's upper jaw and teeth dug up in a Swiss cave dates back more than 14,000 years, and it could be evidence of the oldest domestic dog in the world.

Researchers at Germany's Tubingen University have analyzed the remains recovered in 1873 from the Kesslerloch cave in northern Switzerland, a few miles from the German border. The fragment, from the right side of the animal's skull, is 4 inches long and contains several teeth still in place, said Hannes Napierala, co-author of the research paper recently published in the International Journal of Osteoarchaeology.

Analysis shows the fragment is between 14,100 and 14,600 years old, making it "the earliest indisputable, directly dated evidence of a domestic dog," the archaeologist said.

In 2008, researchers identified another fossil from a Belgian cave as a domestic dog and dated it to 31,700 years ago, more than twice as old as any other such archaeological evidence. But Napierala isn't convinced that find was a domestic dog rather than a wolf with a broader snout, which he said could have evolved because of the availability of larger game rather than through domestication, as the original researchers suggested

The newly dated remains were in the archive of a museum in Schaffhausen, Switzerland, until Napierala and his colleague, zoologist Hans-Peter Uerpmann, borrowed them to subject them to updated scientific analysis. Remains of other ancient dogs are being studied by researchers worldwide, but often they cannot be directly dated because they are too small to be analyzed.

"If you want to be sure, you have to date the find itself, and often there are small amounts of younger material in an archaeological layer, which makes it hard to distinguish the pieces," Napierala said. "Also, to analyze a piece you must be ready to destroy a bit of it; our find is considerably large, so it wasn't a problem."

Napierala said that many canine remains actually belong to wolves, which are today's dogs' ancestors. The size of wolves' teeth has remained stable over the millennia, and the Swiss fragment's dentition is clearly smaller, Napierala said. "These teeth are 0.15 inches shorter than wolves' teeth and have another morphology. It has to be something different," he said, adding that he planned to carry out DNA tests on the Swiss remains.

Napierala said these early dogs were midsize and wolfish-looking, but most probably were already domesticated. The domestication process -- when wolves become distinguishable from dogs -- is hard to pinpoint in space and time, but it is clear that dogs were already part of humans' lives in the late Ice Age.

"Dogs were probably domesticated in several places at the same time. While we can't prove anything, we think it was done unconsciously; they probably found young puppies, liked them and took them to the camps," Napierala said. "Also, since dogs eat meat, they must have been accepted when there was a surplus of food, when the men were able to hunt big animals and were not suffering from hunger."