The oldest fossil
This 3.5-billion-year-old black chert from the Warrawoona Group of Western Australia contains microscopic forms believed by some scientists to be fossil bacteria. If these are actually fossils, they are the oldest-known examples of life. The microfossils resemble modern light-sensitive bacteria, and the rocks in which they are found formed near the surface of a shallow sea. It is thus likely that organisms employing photosynthesis — the use of sunlight for food and energy — were providing oxygen for an evolving atmosphere.
Provided by Prof. Roger Buick, University of Sydney, Sydney, Australia
Keywords: Micropaleontology, Photosynthesis, Bacteria, Fossils, Prokaryotes