A new study on fossil specimens of dog tooth has given researchers new insight on the origin of modern dogs.

Dogs have been domesticated much before humans learned farming. But, nobody was sure when the domestication and the distinction with wolves first happened.

Researchers from Russia have now discovered a 33,000-year-old fossil tooth of a dog that resembles more closely to the modern dog, than to wolves. The study on the fossil tooth was conducted by a team led by Anna Druzhkova from the Institute of Molecular and Cellular Biology, Russian Federation.

The oldest known fossil record of the present-day dog is about 36,000 years old, even though dogs are known to have been domesticated for about 100,000 years.

The fossil of the dog tooth was found in the Altai Mountains in Siberia, which according to UNESCO World Heritage Centre website, were inhabited by humans almost a million years ago.

The fossil specimen called Altai dog (named because it was discovered in this region) was genetically analyzed by researchers. It was found that the fossil tooth of the Altai dog had closer links with modern-day dogs than to wolves.

"Our analyses support the hypothesis that the Altai specimen is more closely related to domestic dogs than to extant wolves," researchers said. The team, however, stressed that more research is needed to confirm the findings.

Previously, research has shown that dogs likely originated in the Middle-East than Asia or Europe as they seem to share genetic traits with Middle-Eastern grey wolves than other wolf populations across the world.The new study provides evidence that dogs may have originated in other parts of the world.

"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," said researchers.

The study is published in the journal PLOS One.