Researchers say they have discovered the remains of ancient life, undisturbed for thousands of years, buried below the ice of an Antarctic lake.

According to a press release by scientific journal Nature, the Subglacial Antarctic Lakes Scientific Access (SALSA) mission discovered the remains of creatures in Antarctica’s subglacial Lake Mercer, a lake covered by a 1,067 metre thick sheet of ice.

SALSA scientists used a high-pressure hot-water drill to cut a small channel through the ice to the lake, which had lain undisturbed for thousands of years – until now only seen through ice-penetrating radar.

While cleaning lake mud off of a temperature-measuring instrument pulled from the water, scientists discovered fragmented remains of creatures that had lived in the lake thousands of years ago.

Though researchers say they were not expecting to find anything more complex than single-cell microbes, in the mud they found the remains of tiny crustaceans, tiny invertebrates called tardigrades, as well specimens that likely come from plants or fungus.

They theorize that the creatures likely inhabited ponds and streams in the nearby Transantarctic Mountains, which pass 50 kilometres south of Lake Mercer, and may have washed into the lake during brief warm periods when the glaciers receded.

Figuring out when and where the creatures lived, and the type of environments they needed to survive would increase our understanding of how Antarctic’s glaciers moved, receded, and grew in cycles between ice ages, scientists say.

The team now plans to carbon date the remains, to try and determine more precisely how long ago they lived, as well as attempt to sequence their DNA.