The fossils have been discovered in a region of western Australia which was once covered by an ocean. Scientists have long speculated that such organisms, which do not need sunlight, preceded the evolution of photosynthesis - but until now there has been no firm evidence. The fossils were found in a geological region known as the Pilbara Craton in a type of sulphide deposit associated with hydrothermal vent systems. They extend the known range of undersea thermal life by more than 2,700 million years, taking it back to what is known as the Archaean era. The twisting thread-like filaments are thought to be the mineralised remains of bacteria which fed on inorganic matter and lived in total darkness at temperatures close to 100C. Birger Rasmussen, from the University of Western Australia, Nedlands, reported the findings in the journal Nature.
Experts say they add an important new piece to the puzzle surrounding the origins of life on Earth.
Keep an eye on the news. Check out the latest headlines on Ananova's video reports.