Oldest-ever DNA shows mastodons roamed Greenland 2 million years ago

Two-million-year-old DNA sequences — the oldest ever obtained — recovered from frozen soil in the northeastern tip of Greenland suggest that the region was once home to mastodons and reindeer that roamed a forested ecosystem unlike any now found on Earth. Reindeers were also unheard of in Greenland — suggesting that DNA could reveal much about ecosystems that was not recorded in the fossil record.