Researchers are reviving deep-sea microbes that have been dormant for millions of years, since the time of the dinosaurs. Because what could go possibly wrong?

If you ask Steven D’Hondt, a professor at the University of Rhode Island’s Graduate School of Oceanography, not very much. “There’s not much risk inherent in it,” he told Digital Trends. “Marine microbes don’t generally infect people, and these are marine sedimentary microbes that have been buried almost 100 million years longer than people have been in the world. So they’re not adapted to infect people.”

The work is pretty fascinating. In the study, an international team of researchers demonstrated that, under the right lab conditions, microbes from ancient sediment can be revived and made to multiply — despite being trapped in starving conditions for unimaginably long periods of time.

The samples were taken by drilling up to 75 meters (almost 250 feet) below the seafloor in close to 6 km (19,700 feet) of water. They were brought up to a ship and analyzed. Each sample was split into subsamples by Yuki Morono of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC). Morono used one subsample to count the number of microbes in the subsample volume while freezing another at ultra-low temperatures and experimenting on another. Back on dry land, Morono later further examined the subsamples in a lab to see how the 100-million-year-old community grew and reproduced when given different types of food.

The discovery challenges our understanding of how little energy it takes for organisms to survive and how long a microbial community is able to live under food-scarce conditions. That could translate to clues about how organisms survive on other harsh worlds, such as Mars.

“As biologists begin to understand the mechanisms that they use to survive, we may better understand how pathogens survive without visible activity in their hosts — like inactive tuberculosis — and how cells survive as they move from one livable habitat to another,” D’Hondt said.

And returning once more to that question of whether this is all a bit risky, Yuki Morono was ready to put minds at ease. “Although the recovered microbes are widely recognized to be low risk, we have been and will be conducting all the experiments in the biologically contained laboratory, to further minimize the risk as close as to zero,” Morono told Digital Trends.

A paper describing the work was recently published in the journal Nature Communications.