Oldest fossil in world ... from 3.7bn years ago

A FOSSIL discovered in Greenland is believed to be from 3.7billion years ago – making it the oldest ever found.

Australian scientists uncovered the structure in a newly melted part of Greenland, on an ancient sea floor, according to a study in the journal Nature.

The discovery shows life may have formed more quickly and easily than once thought.

It may give hope for life forming elsewhere, such as Mars, said coauthor Martin Van Kranendonk of the University of New South Wales and the Australian Centre for Astrobiology. ‘It gives us an idea how our planet evolved and how life gained a foothold,’ he said.

Scientists had thought it took at least half a billion years for life to form after the molten Earth started to cool.

But the professor said it could have happened more quickly, as ‘the newly found fossil is far too complex to have developed soon after the planet’s first life forms’.

After an unusually warm spring

‘Green oceans and orange skies’

revealed rock previously covered in ice, the Australian team found stromatolites – microscopic layered structures often produced by a community of microbes – between 0.4 and 1.6 inches high.

Professor Van Kranendonk described the discovery as ‘the house left behind made by the microbes’. Scientists used layers of ash from volcanoes and zircon with uranium and lead to date it to 3.7billion years ago.

‘It would have been a very different world,’ the professor added. ‘The land was likely black because the cooling lava had no plants, while large amounts of iron made the oceans green. Because the atmosphere had very little oxygen … its predominant colour would have been orange.’

Abigail Allwood, a Nasa astrobiologist who found the previous oldest fossil – 3.4 billion years – said the date estimate seemed right, but that there was not enough evidence to say conclusively that the structure was life and not just a quirk of geology.