The fossilised remains of microbes that lived beside the sea in the earliest chapter of life on Earth have been discovered in a slab of rock in Western Australia.
Researchers found the tiny fossils in rock formations that date to 3.4bn years ago, making them strong candidates to be the oldest microbes found. Some clung to grains of sand that had gathered on one of the first known stretches of beach.
The findings paint a vivid picture of life arising when the first landmasses began to emerge in fragmentary fashion from the oceans. At the time, volcanic eruptions spewed gas and lava, while a blanket of thick cloud greyed the skies. The moon – much closer then than it is today – pulled the oceans into vast tidal surges. There was no breathable oxygen.
“To us it would have seemed like a hellish place to live,” said Prof Martin Brasier at Oxford University, who co-authored a report on the fossils in the journal Nature Geoscience. “To early life, this was paradise. A true Eden.”