A complete genome has been extracted from a 52,000-year-old woolly mammoth, which might bring us closer to resurrecting the species https://www.newscientist.com/article/2439218-woolly-mammoth-dna-exceptionally-preserved-in-freeze-dried-jerky/ The real question is, should we resurrect the long-extinct species? What could go wrong? 
New Scientist · Woolly mammoth DNA exceptionally preserved in freeze-dried 'jerky'
Our ancestors killed them all, and maybe for good reasons. Maybe they were extremely annoying, or would've taken over the world.