Bacteria fossils found in Australia's Pilbara region are planet's oldest, scientists say

GlobalPost
The World

They're being called the planet's oldest fossils — traces of bacteria that lived a record-breaking 3.49 billion years ago found in Australia's remote Pilbara region.

According to the Washington Post, the find may not only move scientists a step closer to understanding early life on Earth, but also aid in the search for life on other planets.

The fossils — referred to by biogeochemist Nora Noffke of Old Dominion University in Norfolk as "our oldest ancestors" — are not petrified body parts, like dinosaur bones.

Rather, they're "textures on the surfaces of sandstone thought to be sculpted by once-living organisms," the Post wrote, left there "a mere" billion years after Earth formed.

The ancient Pilbara region, in the state of Western Australia — now an iron ore mining hub, populated by such major companies as Rio Tinto — was once shoreline and rocks made from sediment piled up billions of years ago are now exposed and available for examination.

Maud Walsh, a biogeologist at Louisiana State University in Baton Rouge, told The Washington Post that while there were older rocks on Earth, the Pilbara find was the "best-preserved sedimentary rocks we know of."

"They are the ones most likely to preserve the really tiny structures and chemicals that provide evidence for life."

Last year scientists published the discovery of 3.4 billion-year-old fossils in the Pilbara’s Strelley Pool.

At the time, according to Australian Geographic, scientists said that at more than 3.4 billion years old, they were the oldest evidence of life on Earth.

Researchers from the University of WA in Perth and Oxford University in the UK said the impressions of likely sulphur-based bacteria were found well preserved between quartz sand grains in prehistoric rocks.

The team reported their research in a paper published in the journal Nature Geoscience.

The group of researchers, including Noffke, responsible for the latest find presented their findings last month at a meeting of the Geological Society of America.

The POst quoted Alan Decho, a geobiologist at the University of South Carolina’s Arnold School of Public Health, as saying:

"It’s not just finding this stuff that’s interesting. It’s showing that the life had some organization to it."

The report claims that the fossils could help those looking for the building blocks of life on Mars.

Remnants of life on the Red Planet might even be better preserved than they are on Earth, according to Harvard University paleontologist Andrew Knoll.

He said that while here, old terrestrial rocks tended to get damaged by the movement of tectonic plates and cooked by the extreme heat of Earth’s depths, Mars — lacking such tectonic activity — was nearly dead geologically.

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