Among the most ancient fossils, one finds those of unicellular organisms which are thought to have lived some 3,500 milion years ago. Traces of their presence were found in 1993 in Australia. Other traces of life dating from 3,800 million years ago were found in Quebec in 2017.
Source: Evidence for early life in Earth’s oldest hydrothermal vent precipitates (2017) / SIMS analyses of the oldest known assemblage of microfossils document their taxon-correlated carbon isotope compositions (2017) / Metabolically diverse primordial microbial communities in Earth’s oldest seafloor-hydrothermal jasper (2022)
