The fungus is not only the oldest example of a fossilized fungus, but also the oldest land fossil yet found.
Researchers have been able to identify the earliest organism living on land and it was nothing else but a tiny, weird looking fungus.
The fossilized fungus dates back to 440 million years and its threads were discovered more than 30 years ago in Sweden and Scotland but these fossil remains had previously gone unidentified. Latest analysis suggested that these fungus filaments are not only the oldest example of a fossilized fungus but also the oldest fossil of a land creature ever known.
The fungus, called Tortotubus, started the process of rotting and soil formation and played a key role in laying the foundation for more complex organisms to thrive on land.
“During the period when this organism existed, life was almost entirely restricted to the oceans: nothing more complex than simply mossy and lichen-like plants have yet evolved on the land,” said principal investigator Dr Martin Smith from University of Cambridge. “But before there could be flowering plants or trees, or the animals that depend on them, the processes of rot and soil formation needed to be established.”
The fossilized fungus looked similar to its modern counterpart and is shorter than a human hair is wide. Initially, threads were thought to be two different types of organisms but when researchers reconstructed their method of growth, it turned out that both these threads represent different growth stages of a single organism.
“After a long time looking at the fossils I eventually realized that it’d be possible to reconstruct the way that the animal grew and work out what its true affinity was.”Dr Smith said.
Tortotubus is likely the oldest known land fossil but it cannot be claimed that it was the actually the first organism to live on Earth.
Fungi is important for consolidating and holding together soils and also help broke down the organic matter in a form where it passes on nutrients to other organisms, working like a fertilizer for early land plants.
“What we can see in this fossil is complex fungal ‘behavior’ in some of the earliest terrestrial ecosystems – contributing to soil formation and kick-starting the process of rotting on land,” said Smith.
“This fossil provides a hint that mushroom forming fungi may have colonized the land before the first animals left the oceans. It fills an important gap in the evolution of life on land.”