The Rhynie chert
A Scottish hot spring floods an early land ecosystem with silica and freezes it in place.
- When
- Known to
- ± 2 million years
- Era
- Devonian, Paleozoic
The 407-million-year-old Rhynie chert preserves the oldest known terrestrial ecosystem in cellular detail: plants standing upright where they grew, with stems, spore capsules and internal tissue intact, alongside mites, springtails, fungi, algae, cyanobacteria and the earliest known fungus-plant symbioses. Nothing else offers this resolution for early life on land, and much of what is known about the transition comes from this one site.