from Phys.org

Scientists find 3.7 billion-year-old fossil, oldest yet

by Seth Borenstein

Scientists find 3.7 billion-year-old fossil, oldest yetIn this photo provided by Laure Gauthiez, taken in July 2012, a field team examine rocks in Greenland.

Scientists have found what they think is the oldest fossil on Earth, a remnant of life from 3.7 billion years ago when Earth’s skies were orange and its oceans green.

In a newly melted part of Greenland, Australian scientists found the leftover structure from a community of microbes that lived on an ancient seafloor, according to a study in Wednesday’s journal Nature .

The discovery shows life may have formed quicker and easier than once thought, about half a billion years after Earth formed . And that may also give hope for life forming elsewhere, such as Mars, said study co-author Martin VanKranendonk of the University of New South Wales and director of the Australian Center for Astrobiology.

“It gives us an idea how our planet evolved and how life gained a foothold,” VanKranendonk said.

Scientists had thought it would take at least half a billion years for life to form after the molten Earth started to cool a bit, but this shows it could have happened quicker, he said. That’s because the newly found fossil is far too complex to have developed soon after the planet’s first , he said.

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