Scientists have identified an extinct relative of the yak from DNA recovered in Siberia's Denisova Cave, adding a new branch to the bovine family tree.

The animal, dubbed "Yak X", was identified from 20 ancient genomes. It diverged from other bovines around 400,000 years ago and became isolated about 250,000 years ago.

The species went extinct roughly 27,000 to 30,000 years ago. The findings were published in the journal Current Biology.

Researchers say the discovery shows how much biodiversity was lost during the last Ice Age. Denisova Cave has previously yielded remains of Neanderthals and Denisovans.

Genetic analysis revealed the yak relative was a distinct lineage, not simply an ancient population of modern yaks. It likely roamed the cold steppes of Siberia.

The study adds to growing evidence that Ice Age Eurasia hosted many large mammals that vanished as the climate warmed and humans spread.

The team plans to sequence more genomes from the cave to map the animal's ancient range.