635 MILLION-year-old mushroom-like microfossil found in China could help Earth recover from the Ice Age

Fungi were previously believed to have appeared around 240 million years ago, but a new discovery has rewritten the timeline of when spore-producing organisms first colonized Earth.

An international team of scientists has discovered a 635-million-year-old mushroom-like microfossil – making it the oldest terrestrial fossil on record – in cavities in rocks in southern China.

Researchers say it evolved during the Ediacaran Period, when the planet was emerging from a catastrophic ice age and the microorganism may have played a key role in its recovery.

Along with other terrestrial microbes, the fungus-like organism had the ability to accelerate chemical time and deliver phosphorus to the oceans, which in turn boosted marine bioproductivity.

An international team of scientists have discovered a 635-million-year-old mushroom-like microfossil – making it the oldest terrestrial fossil ever recorded – in cavities in rocks in southern China

The fossil was discovered in well-studied sedimentary dolomite rocks of the lowest Doushantuo Formation in southern China by scientists from Virginia Tech, Chinese Academy of Sciences, University of Education of the Guizhou and the University of Cincinnati.

Tian Gan, a visiting doctorate. Xiao lab student said: “It was an accidental discovery.

“At that point, we realized that this could be the fossil that scientists have been looking for for a long time.

“If our interpretation is correct, it will be useful in understanding paleoclimatic change and the evolution of early lives.

The fossil was discovered in well-studied sedimentary dolomite rocks of the Lower Doushantuo Formation in southern China.

The preserved fossil has several orders of branches, curved filaments (photo) and ladder-like branching systems

The preserved fossil has several orders of branches, curved filaments and ladder-like branching systems.

When the Ice Age hit the planet, it froze the ocean surfaces to a depth of over a mile and the environment was so harsh that no organism could survive.

The Earth recovered and produced a biosphere that was larger and more complex than before, which has been a mystery to scientists – but the new fossil could ultimately solve the riddle.

Researchers believe the mushroom-like microorganism and others like it are helping to recondition the environment and have done so by using their formidable digestive system.

Fungi have a digestive system capable of recycling essential nutrients and can chemically break down rocks and other stubborn matter using enzymes secreted into the environment – all of which can then be recycled and exported to the ocean.

“Fungi have a mutualistic relationship with plant roots, which helps them mobilize minerals, such as phosphorus,” Gan said.

Fungi have a digestive system capable of recycling essential nutrients and can chemically break down rocks and other stubborn matter using enzymes secreted into the environment – all of which can then be recycled and exported to the ocean (pictured is a computer image of the fossil)

“Because of their connection to terrestrial plants and important nutritional cycles, terrestrial fungi have a critical influence on biochemical weathering, the global biogeochemical cycle and ecological interactions.”

Previous work has suggested that terrestrial plants and fungi formed a symbiotic relationship around 400 million years ago, but the new fossil rewrites the timeline to 635 million years.

Shuhai Xiao, professor of geosciences at Virginia Tech College of Science, said, “The question was, ‘Were there fungi in the earth realm before the rise of land plants.’

“And I think our study suggests so. Our mushroom-like fossil is 240 million years older than the previous record. This is, to date, the oldest record of terrestrial fungi ”.