The most ancient DNA ever sequenced reveals what the Arctic looked like two million years ago when it was warmer.
Today the area in North Greenland is a polar desert, but the genetic material, extracted from soil, has uncovered a rich array of plants and animals.
The scientists found genetic traces of elephant-like mastodons, reindeer and geese that roamed among birch and poplar trees, and of marine life including horseshoe crabs and algae.
The research is published in Nature.
Prof Eske Willerslev, who carried out the study, from the University of Copenhagen and the University of Cambridge said that this mixture of Arctic and temperate species living side by side has no modern equivalent.