The researchers found that this fossil, named the 'Altai dog' after the mountains where it was recovered, is more closely related to modern dogs and prehistoric canids found on the American continents than it is to wolves.
The findings by Anna Druzhkova from the Institute of Molecular and Cellular Biology, Russian Federation, and colleagues from other institutions could indicate that dogs were domesticated around 33,000 years ago.
The point at which wolves went from wild to man's best friend is widely debated, though dogs were well-established in human societies by about 10,000 years ago.
The new study evaluated the relationship of the Siberian fossil to modern dogs and wolves based on DNA sequence.
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The researchers compared the genetic sequences from the Altai specimen with gene sequences from 72 modern dogs of 70 different breeds, 30 wolves, four coyotes and 35 prehistoric canid species from the Americas.
They found that the Altai canid is more closely related to modern domestic dogs than to modern wolves.
If the Altai dog was really domesticated, it would push back the origin of today's house pets more than 15,000 years and move the earliest domestication out of the Middle East or East Asia, as previous studies have suggested.
However, the analysis was limited to only a portion of the genome, the researchers wrote.
"These results suggest a more ancient history of the dog outside the Middle East or East Asia, previously thought to be the centers where dogs originated," researchers said in a statement.