An article published in the journal “Science Advances” reports an abundance of ammonia-oxidizing archaea in microbial communities in sediments beneath the seafloor of the North Atlantic Ocean. A team of researchers led by William Orsi of the Ludwig-Maximilians-Universitaet (LMU) in Munich, Germany, discovered that archaea not only survived for millions of years in sediments that can reach over two kilometers below the ocean floor but adapted to those conditions better than bacteria and could play an important role in the geochemical cycles of carbon and nitrogen in that ecosystem.