The hidden world of fungi in archaeology

By Mark Ramsdale, Head of Training at the MRC-Centre for Medical Mycology, University of Exeter, and Chair of the BMS Fungal Education and Outreach Committee

Fungi might seem like an odd subject to discuss in relation to archaeology, but these remarkable organisms may hold the key to many historical secrets.

Fungi are incredibly resilient. Viable fungal spores have been found preserved in Antarctic ice-cores dating to over 3 million years ago. This extraordinary longevity means that fungi can provide a biological window into the distant past, offering clues about ancient environments and ecosystems. With modern sequencing technologies that can be used to detect and identify fungal DNA, and biochemical techniques that can detect trace quantities of fungal metabolites, it is possible to identify species present at archaeological sites and build up a better picture of distant lives and cultural practices.

Fungi, dung and ancient agriculture

The presence of Coprophilous fungi (dung loving fungi) in sediments at archaeological sites has been used as a marker to understand the past distribution of megaherbivores (cattle, deer, mammoths). The detection of Sporormiella spores can help archaeologists understand the interactions between humans and agriculturally important animals. For example, a high concentration of Sporormiella spores in a particular sediment layer might indicate a period of abundant megaherbivore activity, which could correlate with human migratory and hunting patterns or the development of early settled agricultural societies.

Fungi and forensics

Fungi can provide critical information in forensic archaeology. The presence and growth patterns of fungi on ancient and recent cadavers might indicate the season of death. Fungi often colonize decomposing corpses, forming distinctive mildew spots, ultimately converting bodies into mouldy cadavers.. Heavily decomposed bodies, in particular those that are highly mummified, often present visible fungal growth that can easily be identified. Since specific fungal spores are more prevalent in specific seasons, this information can allow forensic scientists to estimate the time of year a person died. Some fungi known as ammonia fungi grow on the corpses of dead animals and latrines, providing markers for their presence when visible fungal fruitbodies grow above-ground. This knowledge could be invaluable in solving both historical and modern mysteries.

Fire and medicine: Ötzi the iceman

The well-preserved body of Ötzi the Iceman found on the Austrian-Italian border, dates to around 3300 BCE. Among his possessions were fungi with fire-making and medicinal properties. The tinder fungus (Fomes fomentarius) and birch polypore (Fomitopsis betulina) found with Ötzi were likely used for starting fires, treating wounds, and possibly as an antibiotic and dewormer. This discovery underscores the practical and medicinal uses of fungi in ancient times and the importance placed upon them given the associated artefacts.

Fungi as valued resources in the afterlife

Fungi such as Ganoderma sichuanense (also known as reishi or lingzhi) were highly valued in ancient Chinese culture for their medicinal and spiritual significance. Ganoderma fungi have been found in Neolithic tombs (6517-4508 BCE), suggesting they were used in burial practices to ensure the health and protection of the deceased in the afterlife. Discoveries like these directly highlight the cultural importance of fungi in ancient societies.

The "Curse of the Pharaohs"

The discovery of King Tutankhamun’s tomb is famous not just for its treasures but also for the so-called "curse of the pharaohs." Examination of fungi from Egyptian tombs such as Tutankhamun’s and Ramses II have revealed 89 different species. The fungi include a number of pathogenic Aspergillus species. In 1970, the tomb of King Casimir IV of Poland, who died in 1492, was opened, and within weeks, ten of the twelve researchers present at the excavation died. This incident has often been linked to the presence of fungal spores within the sealed tomb including those of Aspergillus flavus, a mould that produces aflatoxins.

Psilocybin and Ancient Art

The oldest known depictions of fungi are found in prehistoric rock art from Tassili n'Ajjer in Algeria, dating to approximately 9000–7000 BCE. These ancient paintings are believed by some to depict psychedelic mushrooms and scenes of transformation possibly associated with their use. This rock art provides evidence that prehistoric humans were aware of and possibly utilized fungi, potentially for their hallucinogenic properties, in their spiritual or ritualistic practices. The exact species of mushrooms depicted are unclear but may include members of the genus Psilocybe, which contains various species known for their psychoactive effects. The ancient Maya and Aztec civilizations also used Psilocybe mushrooms in spiritual and healing practices, as evidenced by mushroom stones and carvings found in Mesoamerican archaeological sites.

Iron-age bog men and Eleusinian goddesses

In 1952, Danish peat cutters working near the Danish village of Grauballe discovered the remains of a corpse of a man. Radiocarbon dating showed that he died in the late Iron Age, somewhere between 310 and 55 BCE. Grauballe man’s preservation (and that of other bogmen) is a result of the unique interplay of environmental factors in the peat bog, with fungi playing a crucial role.

Grauballe man’s last meal contained grasses infected with the sclerotia of the ergot fungus Claviceps purpurea. When consumed by humans in sufficient quantities, ergot can cause hallucinations, muscle spasms, and fever, as it contains lysergic acid, which is necessary for the synthesis of the drug LSD. Grauballe man’s death is easily attributed to the slashing of his throat – but why was he killed? Did he display bizarre behaviours that might have marked him out someone possessed by evil spirits as a result of ingesting the ergot alkaloids?

Alternatively, might he have intentionally ingested the fungus in order to bring about mystical experiences. This might seem unlikely, but fragments of Claviceps purpurea have been found in a temple dating to the 4th–2nd century BCE that was dedicated to the Eleusinian Goddesses, Demeter and Persephone. At the sites, Ergot sclerotial fragments were found inside a vase and within the dental calculus of a jaw of a 25-year-old man. This finding seems to strongly support the hypothesis of ergot as an ingredient of the Eleusinian kykeon – the mystical drink of heroes, linked to most famous of the secret religious rites of ancient Greece!

Fungi and degradation of archaeological finds

Of course, the presence of fungi in archaeological specimens is not always helpful. Fungi such as Aspergillus, Penicillium, and Cladosporium play a crucial role in the degradation of bones. and paper. These fungi produce enzymes (cellulases and proteinases) as well as organic acids that break down components of bones and ancient manuscripts, making preservation a significant challenge. Understanding these processes is vital for developing strategies to conserve archaeological finds and protect our historical heritage.

Take home message

An awareness of fungi can provide powerful new perspectives that aid in the interpretation of past events and provide clues to the daily lives of peoples around the world. From helping preserve (or destroy) historical artifacts to providing clues about ancient environments and cultures, an understanding of fungi can play a vital role in uncovering the secrets of our past.