Geomyces pannorum is a yellow-brown filamentous fungus of the phylum Ascomycota commonly found in cold soil environments including the permafrost of the Northern hemisphere. A ubiquitous soil fungus, it is the most common species of the genus Geomyces; which also includes G. vinaceus and G. asperulatus. Geomyces pannorum has been identified as an agent of disfigurement of pigments used in the 15,000-year-old paintings on the walls of the Lascaux caves of France. Strains of Geomyces have been recovered from the Alaskan Fox Permafrost Tunnel and radiocarbon dated to between 14,000 and 30,000 years old.