Evolution

It is thought that AMF played significant role on the adaptation of plants from aquatic to terrestrial ecosystems. Fossil records indicate arbuscular mycorrhizal-like symbiosis developed some 450 millions of years ago (early Devonian). In this sense, AMF became a obligate symbionts in order to complete all their ontogenic cycle. Glomites rhyniensis is the ancestor of AMF. This fungus was found in preserved roots of Aglaophyton major, Rhynia, and Nothia.

Ectomycorrhizal fungi are thought to have evolved from saprotroph fungi in the Paleozoic Era. Fossil records for Ascomycetes and Basidiomycetes start in the Silurian and Permian Periods, respectively.