|
 A study published on Wednesday described microfossils of a
subterranean fungus called Tortotubus that was an early landlubber
at a time when life was largely confined to the seas, including
samples from Libya and Chad that were 440 to 445 million years old.
The fossils represented the root-like filaments that fungi use to
extract nutrients from soil. Tortotubus possessed a cord-like
structure similar to some modern fungi. It was unclear whether it
produced mushrooms.
Tortotubus helped set the stage for complex land plants and later
animals by triggering the process of rot and soil formation.
 "By building up deeper, richer, more stable soils, Tortotubus would
have paved the way for larger, more complex green plants to quite
literally take root, in turn providing a food source for animals and
allowing the escalation of terrestrial ecosystems," said
paleontologist Martin Smith of Britain's Durham University, who
conducted the research while at the University of Cambridge.
These fossils, also discovered in other places including Sweden,
Scotland and New York state, reflect the humble beginnings of life
on the land.
While the primeval oceans were teeming with life including jawless
fish, arthropods, squid relatives, jellyfish and more, the land was
barren and void. To survive on land, organisms had to be able to
tolerate desiccation, ultraviolet light exposure and limited
nutrients.
Tortotubus may not have been the very first land pioneer, but no
fossils have been found of earlier terrestrial organisms.
[to top of second column] |
"By the time Tortotubus went extinct, the first trees and forests
had come into existence," Smith said. "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 studied fossil filaments so small that thousands would fit on
the head of a pin. The filaments would have gone through the ground
in search of food in the form of dead organic matter. The original,
non-fragmented organism could have been a fungal network measuring
yards (meters) across, Smith said.
The research was published in the Botanical Journal of the Linnean
Society.
(Reporting by Will Dunham; Editing by Sandra Maler)
[© 2016 Thomson Reuters. All rights
reserved.]
Copyright 2016 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.
 |
