Scientists from the University of Bologna have discovered microfossils – the fossilized remains of microorganisms that are 3.42 billion years old.

Researchers from the University of Bologna have found fossils in the oldest sedimentary rocks on Earth in the Barberton Greenstone Belt in South Africa.

According to the authors, microorganisms lived in underwater cavities, which received water from warm hydrothermal springs, in an oxygen-free environment, and fed on methane. This is the oldest evidence of life on Earth today.

We found exceptionally well-preserved evidence of fossilized microbes that seemed to thrive along the walls of cavities created by warm water from hydrothermal systems several meters below the seabed. Surface habitats heated by volcanic activity were likely home to some of Earth’s earliest microbial ecosystems, and this is the oldest example we have to date.

Barbara Cavalazzi, professor and lead author of the study

The authors believe that microorganisms lived in shallow water, near the outlet of underwater hydrothermal vents. The interaction of cool seawater with warm underground fluids created a chemical-rich habitat.

Chemical analysis showed that the fibers of organisms contained most of the basic elements necessary for life, and the concentrations of nickel correspond to the content of this trace element in modern prokaryotes, such as archaea, which live in the absence of oxygen and use methane for their metabolism.

Scientists have suggested that the same microbes can be found on Mars, where billions of years ago there were conditions of existence similar to our planet.