Japanese scientists say they have revived microbes that have been at rest for more than 100 million years.
Tiny organisms have survived on the seabed in the South Pacific – sediments that lack nutrients but have enough oxygen to survive.
Microbes are some of the simplest organisms on earth, and some can live in extreme environments where more advanced life forms cannot survive.
After the scientists incubated, the microbes began to eat and multiply.
The study was led by the Japan Marine and Land Science and Technology Agency and was published in the journal Nature Communications.
“When I found them, I was first skeptical as to whether the conclusions were from some mistake or a failure in the experiment,” lead author Yuki Morono told AFP.
“It simply came to our notice then that there was no age limit [organisms in the] seabed biosphere ”.
Professor and co-author of the study, Steven D’Hondt of the University of Rhodes, said the microbes came from the oldest specimens taken from the seabed.
“There are still living organisms in our oldest drilled sediments with the least amount of food. They can wake up, grow and multiply, ”he said.
Previous studies have shown how bacteria can survive in harsh places, including around underwater openings that lack oxygen.
Mr Morono said the new finding shows that some of the simplest structures on Earth “do not really have a concept of life expectancy.”