Thuchomyces (sometimes mistakenly called “Thucomyces”) is a genus of Archean fossils from the Witwatersrand of South Africa, and is the earliest macroscopic land life known.

[1] The generic name derives from thucholite, the carbonaceous material which Thuchomyces is preserved in, and the Ancient Greek word "myces", meaning "fungus".

[1] The internal structure of Thuchomyces consists of a network of hyphae, made of intensely branching cells possibly connected via anastomoses.

The outer layer of the organism consists of highly agglutinated hyphae with a layer of loose tissue inside it, alongside a "central cord" observed in immature specimens which disappears with age.

[3] Taking into account various features such as ventifacts, the concentration of carbon-13 in the rock and other geological features, the sediments Thuchomyces is known from are interpreted as being a wind-blasted desert environment crossed by ephemeral streams, which was occasionally flooded.