Mystery surrounds 18,000-year-old pup
The remains of an ancient "puppy" with whiskers, eyelashes, velvety nose and sharp teeth still intact has left scientists flummoxed.
The two-month-old canine is an astonishing 18,000 years old and was discovered near-perfectly preserved in Siberian permafrost.
But detailed DNA tests have so far failed to establish its species.
Experts are uncertain whether it is an Ice Age dog or a wolf - or perhaps an example of the evolutionary transition from the latter to the former.
So far tests in Sweden have drawn a blank.
The young male snarling with distinctive arrowhead fangs was found in summer 2018 in a lump of frozen ground near the Indigirka River, northeast of the world's coldest city, Yakutsk.
The cause of death has not been established, but experts say the young beast does not appear to have been in distress when it died during the Upper Palaeolithic era.
Russian scientists provided samples from the ancient canine to the Swedish Centre for Palaeogenetics (CPG) in order to establish whether it was a wolf cub - as initially suspected - or dog.
Dr Sergey Fedorov said: "The centre has Europe's largest DNA bank of all canines from around the globe, yet in this case they could not identify it from the first try.
"This is intriguing."
"What if it's a dog? We can't wait to get results from further tests."
The Swedish scientists confirmed in a tweet that the animal was 18,000 years old but added: "So far, we have sequenced it's genome to 2X coverage.
"But we still can't say if it's a wolf or a dog.
"Maybe it's the common ancestor? More sequencing is needed."
The puppy has been named Dogor - which means friend in the local Yakut language in this part of Siberia.
But the name also expresses the uncertainty of whether it is a Dog … or something else.
Dr Fedorov, from the Institute of Applied Ecology of the North at Russia's North-Eastern Federal University, said further analysis would be carried out.
One theory is the beast could represent a transitional stage from a wolf to a dog, reported The Siberian Times.
Some modern dogs probably descended from just one population that lived continuously in Europe for millennia, according to some scientists.
They are seen as having evolved from an extinct wolf species some 15,000 to 40,000 years ago.
Others say the likely evolution is earlier.
This article originally appeared on The Sun and was reproduced with permission