A tiny subterranean fungus named Tortotubus was an early land-dwelling organism on Earth when life was mostly confined to the seas.

A study published Wednesday in the Botanical Journal of the Linnean Society described the oldest-known microfossils of the fungus, tiny fragments that are shorter than a single hair’s width.

These fossils, which represented the root-like filaments Tortotubus use to take away nutrients from the soil, include samples from Chad and Libya that were 440 to 445 million years old.

Photo: Smithsonian/Martin R. Smith
Photo: Smithsonian/Martin R. Smith

Similar to some modern fungi, Tortotubus had a cord-shaped structure. Study author did not specify if that fungi produced mushrooms, but the paper states that it triggered the process of rot and the formation of soil, contributing to the creation of complex land plants and later animals.

Paleontologist Martin Smith of Britain’s Durham University said the fungus built up deeper, richer and more stable soils, setting the way for larger green plants to take root. Tortotubus provided an important food source for animals and allowed the escalation of ecosystems on Earth, Smith explained. He led the study at the University of Cambridge.

Tortotubus reflect the origins of life on the land

The study findings represent such an important scientific discovery because these fossils reflect the beginnings of life on the land. The fungal remnants were also discovered in Scotland, Sweden, and New York State.

When life was starting to appear in the primeval oceans, the land was infertile and empty. Organisms on land had to survive by resisting desiccation, nutrients scarcity, and ultraviolet light exposure while jawless fish, arthropods and jellyfish were emerging in the seas.

Researchers say that no fossils older than Tortotubus have been found of earlier land organisms, meaning that this fungus may have been the very first terrestrial pioneer.

“This humble subterranean fungus steadfastly performed its rotting and recycling service for some 70 million years, as life on land transformed from simple crusty green films to a rich ecosystem that wouldn’t look out of place in a tropical greenhouse today”, Smith said.

He and his research team examined fossil filaments so tiny that thousands of them would easily fit on a pin head. Smith noted that the non-fragmented organism could possibly have been a fungal network measuring yards across.

Source: Reuters