The evidence of ancient bacteria were found in rocks that are extremely rare, and If scientists happen to stumble upon them, they're almost always compromised by forces of nature.
The new study in Australia revealed a well-preserved remains of an actual and complex ecosystem in a rock that is suppose to be 3.5 billion year old.
The Pilbara district of Western Australia, where the amazing ancient finding was discovered, is quite famous geological region, where the scientists get some pretty good insights of the early evolution of life on Earth.
On the rock image above, you can see the so called 'polygonal oscillation cracks'. The rock is part ofc the 3.48 billion years old Dresser Formation. These kind of sedimentary structures are natures archives, as they document ancient microorganisms. The Dresser Formation records a setting, similar to the environments occurring on the Mars. Findings like this, help us understand how the earliest life on Earth started evolving.