Discovered in 2018 in a lump of frozen mud near the city of Yakutsk, the puppy is unusually well preserved, with its hair, teeth, whiskers and eyelashes still intact.

"This puppy has all its limbs, pelage - fur, even whiskers. The nose is visible. There are teeth. We can determine due to some data that it is a male," Nikolai Androsov, director of the Northern World private museum where the remains are stored, said at the presentation at the Yakutsk's Mammoth Museum which specialises in ancient specimens.

In recent years, Russia's Far East has provided many riches for scientists studying the remains of ancient animals.

As the permafrost melts, affected by climate change, more and more parts of woolly mammoths, canines and other prehistoric animals are being discovered. Often it is mammoth tusk hunters who discover them.

"Why has Yakutia come through a real spate of such unique findings over the last decade? First, it's global warming. It really exists, we feel it, and local people feel it strongly. Winter comes later, spring comes earlier," Sergei Fyodorov, scientist with the North Eastern Federal University, told The Associated Press.

"And the second very serious, deep reason, of why there a lot of finds is the very high price of mammoth tusk in the Chinese market."

When the puppy was discovered, scientists from the Stockholm-based Centre for Palaeogenetics took a piece of bone to study its DNA.

"The first step was of course to send the sample to radio carbon dating to see how old it was and when we got the results back it turned out that it was roughly 18,000 years old," Love Dalen, professor of evolutionary genetics at the center, said in an online interview.

Further tests, however, left the scientists with more questions than answers - they could not definitively tell whether it was a dog or a wolf.

Dalen said scientists were about to do a third round of genome sequencing, which might solve the mystery.

Australian Associated Press