DNA Reveals Unknown Ice Age Yak Relative

Researchers identified a previously unknown Ice Age bovine, nicknamed “Yak X,” from fragmented bones found in Denisova Cave and other sites in Siberia. Ancient DNA analysis produced 20 genomes and showed the animal was distinct from known species, with a lineage that diverged from the ancestors of modern yaks about 400,000 years ago. The remains span roughly 250,000–200,000 years ago to about 27,000 years ago, documenting the animal’s presence alongside Ice Age megafauna; researchers say Denisovans may also have hunted it. The species has not received a formal scientific name because genetic evidence alone is not considered sufficient for its official description.