If all of this is true, then it is really astonishing.
But there's something in this article that sounds very hard to accept:
DNA is extremely fragile, it is very hard to imagine it surviving 50 000 years, even in Siberian ice. It is even harder to imagine someone to be able to sequence the entire genome of such species. And also: how can they affirm there's no contamination from human DNA (e.g.: bones remaining from cannibalism)?
I'll wait to hear more confirmations of this story.
The article does not say that they sequenced the whole "ancient" genome and indeed it is quite unlikely that they did so. They probably matched lots of isolated segments, however.
As for contamination issues... Nothing beats the original article when working out the odds of such a thing.
But there's something in this article that sounds very hard to accept: DNA is extremely fragile, it is very hard to imagine it surviving 50 000 years, even in Siberian ice. It is even harder to imagine someone to be able to sequence the entire genome of such species. And also: how can they affirm there's no contamination from human DNA (e.g.: bones remaining from cannibalism)?
I'll wait to hear more confirmations of this story.