Prehistoric Fungi

Fungi the size of trees: PrototaxitesThere is much written about the prehistoric ancestors of many organisms including mammals, reptiles, birds and more. But what of fungi? Not much was known to have survived which is perhaps odd given the plant like structures we see today, but on closer examination tiny microscopic threads (hyphae) have been found as fossils and remains captured in amber - though there is often debate over whether this type of structure is a true fungus or something very similar such as a filamentous algae. The earliest signs of fungi are 1430 million years old.

Largest Prototaxite fossil foundThere is some evidence to support the development of the ability by fungi to digest wood ended the development of coal.

But what of the larger structures? Where were the mushrooms in the fossil record? We know most fungi do not fossilize well, but in the late 20th century scientists started to look more closely at a large plant-like organism (Prototaxites)that had originally been thought to be a conifer-like tree or algae (specimen collected in 1843). New evidence presented by Hueber in 2007 concluded that based on the preserved morphology Prototaxites was a fungus - a huge tree-like fungus which predates the development of the trees we see today. 

The genus Prototaxites describes terrestrial organisms known only from fossils dating from the Silurian and Devonian, approximately 420 to 370 million years ago. Prototaxites formed large trunk-like structures up to 1 metre (3 ft) wide, reaching 8 metres (26 ft) in height, made up of interwoven tubes just 50 micrometres (0.0020 in) in diameter. Whilst traditionally very difficult to assign to an extant group of organisms, current opinion is converging to fungal placement for the genus. It might have had an algal symbiont , which would make it a lichen rather than a fungus in the strict sense.

Giant Devonian fossil

Wikipedia

We can thus envisage a time hundreds of millions of years ago when fungi dominated land and sea both in quantity and in physical size. Fungi were well placed to take advantage of the arrival of newer life forms such as trees and even animals.

We will present a series of articles and links in this new section that illustrate what we know about this fascinating time in earth's history.

Prehistoric articles