Although researchers can't be exactly sure how old the bacteria are — or how they reproduce — microbiologists at Aarhus University in Denmark posit that the ancient organisms could be anywhere from several thousand to millions of year old, The Washington Post's Joel Achenback reports.
The bacteria, found living in sediments that formed 86 million years ago, have extremely slow metabolisms and are able to survive by living on very small amounts of energy.
"The slow rate of reproduction means that they cannot evolve at the same speed as bacteria in friendlier, energy-rich, nutrient-thick settings. That means, in turn, that they may preserve more primitive genetic features than other bacteria," scientist Robert Hazen told Achenback.
The ability of bacteria to stay alive in such a nutrient-starved environment supports the idea that similar organisms could live on other planets, requiring very little to sustain life.