The oldest confirmed fungi fossils have been identified in a Belgian museum, providing vital evidence for how life on Earth evolved.
The fossils are between 715 and 810 million years old, making them more than 250 million years older than the previous confirmed record holder. Steeve Bonneville at the Free University of Brussels says the fossils had been languishing in Belgium鈥檚 Royal Museum for Central Africa for decades without anyone analysing them, having been originally discovered in what is now the Democratic Republic of the Congo.
Bonneville and his colleagues were聽initially unsure if the fossils, which are trapped between pieces of rock, were fungal or bacterial. The fossils are dark and characterised by networks of filaments. The key to determining their fungal origins was to find out if these networks are made of chitin, a polymer present in the cell walls of all fungi and not present in bacteria.
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By looking at various sections of the rock using electron and fluorescence microscopy to identify the presence of chitin, the researchers were able to show beyond reasonable doubt that these fossils are fungal.
The discovery backs up prevailing theories about the origins of life on Earth. 鈥淲e know that the carbon cycle changes globally around 500 and 800 million years ago and fungi were always suspected to be partners of the first plants to colonise Earth,鈥� says Bonneville, but previously confirmed fungi fossils were too young to support this theory.
Jonathan Leake at the University of Sheffield, UK, says he believes that older fungi fossils have been discovered but they haven鈥檛 yet been chemically confirmed to be fungi. 鈥淭he study puts a firmer confirmatory date on the early origins of fungi before 750 million years old,鈥� he says.
Bonneville is looking at other fungi fossils and hopes to confirm even older fossils soon.
Science Advances
