'Yak X': ancient DNA names a lost Ice Age giant from bone scraps in a Siberian cave

The bones were too broken to identify — small fragments from Denisova Cave in Siberia's Altai Mountains, a place already famous for an ancient human lineage. But DNA does not need a complete skeleton. Swedish-led researchers at the Centre for Palaeogenetics read 20 ancient genomes from fragments found in the cave and nearby sites and recognised something nobody knew existed: a large Ice Age mammal, closely related to today's yak, whose lineage split from the yak's ancestors about 400,000 years ago and which lived from at least 250,000 years ago until about 27,000 years ago. 'It is unusual, especially to recognise a large mammal species from small, unidentifiable fragments,' says senior author Love Dalén. The study is published in Current Biology.