Short answer
Fungi are among the oldest complex life forms on Earth. Microscopic fossils from Arctic Canada suggest fungi existed around a billion years ago. Fungi partnered with the first land plants more than 400 million years ago, the oldest known fossil mushroom is about 115 million years old, and genetic evidence suggests psilocybin-producing mushrooms appeared roughly 65 million years ago, around the time the dinosaurs died out.
Key takeaways
- Fossil fungi from Arctic Canada are dated to around a billion years ago.
- Fungi helped plants move onto land, forming root partnerships still visible in 407-million-year-old fossils.
- The oldest known mushroom fossil, from Brazil, is about 115 million years old.
- Psilocybe appears to date back about 65 million years.
The fungal timeline
| Approximate date | What happened | Confidence |
|---|---|---|
| 2.4 billion years ago | Fungus-like filaments preserved in ancient volcanic rock in South Africa2 | Contested |
| About 1 billion years ago | Microscopic fungal fossils, Ourasphaira, in Arctic Canada1 | Strong but debated |
| 407 million years ago | Fungi partnering with early land plants, preserved in Scotland's Rhynie chert | Well established |
| 252 million years ago | A possible spike in fungal remains after the Permian mass extinction6 | Debated |
| 115 million years ago | Oldest known fossil mushroom, Gondwanagaricites magnificus, in Brazil3 | Well established |
| About 65 million years ago | Origin of the genus Psilocybe and psilocybin, based on genetics4 | Genetic estimate |
The first fungi
The oldest widely accepted fungal fossils are tiny, branching structures called Ourasphaira giraldae, found in shale from Arctic Canada and dated to roughly a billion years ago. Researchers identified chitin in their cell walls, a hallmark of fungi.1 That's hundreds of millions of years before the first animals with skeletons.
Some scientists have proposed even older candidates, like 2.4-billion-year-old filaments preserved in volcanic rock, but whether those are fungi is hotly debated.2
How fungi helped conquer land
When plants first moved out of the water, they didn't have real roots. Fungi filled the gap. In the 407-million-year-old Rhynie chert of Scotland, among the best-preserved early land ecosystems on Earth, you can see fungi living inside early plant tissues in partnerships that look a lot like the root fungi most plants still depend on today. The fungi helped pull water and minerals from rock and soil; the plants paid them in sugar. That deal is still running.
The same rock layer holds Prototaxites, a trunk-like organism up to about 26 feet tall that was long thought to be a giant fungus. A 2026 study argued it wasn't a fungus at all, but a member of an extinct lineage of life.5
The oldest mushroom
Mushrooms almost never fossilize. They're soft and rot within days. That makes Gondwanagaricites magnificus remarkable: a gilled mushroom preserved in limestone in northeastern Brazil, about 115 million years old. It's the oldest known fossil mushroom and was preserved by being replaced with minerals, likely after falling into a salty lagoon.3 A handful of other ancient mushrooms survive in amber.
When psilocybin appeared
There are no psilocybin fossils, so scientists use DNA instead. A 2024 study, the largest genetic survey of the genus to date, estimated that Psilocybe arose around 65 million years ago, close to the asteroid impact that ended the age of dinosaurs. The researchers also found two distinct arrangements of the psilocybin genes, suggesting the ability to make psilocybin may have been acquired more than once.47
In other words, magic mushrooms were growing for about 65 million years before any human ate one. For the human chapter, see the history of magic mushrooms.
Common questions
Why are mushroom fossils so rare?
Mushrooms are soft, watery, and short-lived, so they almost always rot before they can fossilize. Most fossil fungi are microscopic threads and spores preserved in special conditions, like silica-rich hot springs or amber.
Was Prototaxites a giant fungus?
For decades, scientists thought this 400-million-year-old organism, which grew up to about 26 feet tall, was a giant fungus. A 2026 study in Science Advances found its chemistry and structure don't match fungi and suggested it belonged to an extinct, unknown branch of life. The debate isn't fully closed.
Are fungi older than plants?
Fungi and plants both have ancient roots, and the exact order is debated. What's clear is that fungi were on land at least as early as the first plants and were essential to their success.
Sources
- Loron CC, et al. Early fungi from the Proterozoic era in Arctic Canada. Nature. 2019. doi.org/10.1038/s41586-019-1217-0
- Bengtson S, et al. Fungus-like mycelial fossils in 2.4-billion-year-old vesicular basalt. Nature Ecology & Evolution. 2017. doi.org/10.1038/s41559-017-0141
- Heads SW, et al. The oldest fossil mushroom. PLOS ONE. 2017. doi.org/10.1371/journal.pone.0178327
- Bradshaw AJ, et al. Phylogenomics of the psychoactive mushroom genus Psilocybe and evolution of the psilocybin biosynthetic gene cluster. PNAS. 2024. doi.org/10.1073/pnas.2311245121
- Smithsonian Magazine. This mysterious 407-million-year-old fossil may represent a previously unknown branch of life. January 2026. smithsonianmag.com
- Visscher H, et al. The terminal Paleozoic fungal event: evidence of terrestrial ecosystem destabilization and collapse. PNAS. 1996. doi.org/10.1073/pnas.93.5.2155
- University of Utah. Psychoactive psilocybin's evolution in magic mushrooms. January 2024. attheu.utah.edu
This article is for education only and is not medical or legal advice. Psilocybin is a Schedule I substance under U.S. federal law. Talk with a licensed clinician before making decisions about your health. In a crisis, call or text 988.