It is three times older than the first dinosaurs. It is a microfossil that is very similar to a mushroom. It was formed at the end of an ice age about 635 million years ago. It is the oldest terrestrial fossil in the world. The results were published in Nature communication. The article is called Cryptic terrestrial fungal fossils of the early Ediacaran Period.
The investigation is being led by Shuhai Xiao. He is Professor of Earth Sciences at the Virginia Tech College School of Science. Collaboration with Tian Gan, assistant in his laboratory. It shows one of the most important roles that mushrooms could have played. Nothing less than helping the earth recover from an ice age.
The frozen world
They were found in southern China. They are small, filamentous-looking fossils, one of the main characteristics of mushrooms. “It was a chance discovery,” explains Gan. “This will be very helpful in understanding paleoclimate changes and the early evolution of life,” he adds.
The Ediacaran period developed 635 to 542 million years ago. Our planet was recovering from a catastrophic ice age. The climate hypothesis states that our planet was submerged in a global glaciation in which average temperatures fluctuated around -50 ° C. The oceans and continents were covered by a thick layer of ice. An incredibly harsh environment for virtually every living organism, except for a few microscopic life forms that could thrive. How did life get back to normal?
Tian and Xiao are certain that these microscopic cave dwellers helped. One of the keys to this statement is based on his impressive digestive system. They can chemically break down rocks and other resistant organic matter that can later be recycled and exported to the ocean.
Survivors
Sixty years ago, few believed that microorganisms such as bacteria and fungi could be preserved as fossils. With this mere discovery, new questions arise. “It’s always important to understand organisms in an environmental context,” says Xaio. ‘We have a general idea of how these microorganisms lived in small cavities in dolomite rocks. However, little is known about how exactly they lived and how they were preserved. How can fungal organisms that lack bones or shells be preserved in the fossil record? ‘
The world’s oldest terrestrial fossil isn’t necessarily a mushroom. There is no absolute certainty. Xiao explicitly refers to them as “fungal organisms”. Research on these strange microfossils is ongoing. “But it is the best interpretation of the data we have right now,” concludes Xiao, leaving the door open to all possibilities.
