Evolutionary diversification of paleoproterozoic prokaryotes: New microfossil records in 1.88 Ga Gunflint Formation

•Five new microfossils were discovered in the 1.9 Ga Gunflint Formation, Canada.•New morphological and geochemical data proved the biogenicity of microfossils.•Some microfossils showed early acquisition of dormancy and nutrient storage function.•Novel microfossils with cell projection show eukaryotic affinity morphologically.•Early eukaryotic evolution coincidentally occurred with prokaryotic diversification.