'A load of old rot': Fossil of oldest known land-dweller identified

""This fossil provides a hint that mushroom-forming fungi may have colonised the land before the first animals left the oceans," said Smith. "It fills an important gap in the evolution of life on land."

Filaments of Tortotubus. Credit: Martin R. Smith

Filaments of Tortotubus.

Credit: Martin R. Smith

Source: https://www.sciencedaily.com/releases/2016/03/160302082245.htm

" But before any complex forms of life could live on land, there needed to be nutrients there to support them. Fungi played a key role in the move to land, since by kick-starting the rotting process, a layer of fertile soil could eventually be built up, enabling plants with root systems to establish themselves, which in turn could support animal life. By reconstructing how the organism grew, he was able to show that the fossils represent mycelium -- the root-like filaments that fungi use to extract nutrients from soil."