Rhynie chert

The Rhynie chert is a Lower Devonian fossil deposit near the village of Rhynie in Aberdeenshire. It lies in a small field covered by at least a metre of soil, making direct access difficult. A second unit, the Windyfield chert, sits about 700 metres away. The site extends for at least 80 metres along its length and 90 metres downwards. It is protected as a Site of Special Scientific Interest, so collecting is not allowed. The chert is remarkable for its age and detail. Formed about 410 million years ago, it captures an early stage in the colonisation of land. The fossils show extraordinary preservation, with individual cell walls visible in polished pieces. Stomata have been counted, lignin remnants detected, and book lungs of trigonotarbids seen in cross-sections. Fungal hyphae can be seen entering plant material, acting as decomposers and symbionts. Visitors find a landscape shaped by ancient hot springs. The chert preserves an ecosystem that grew around silica-rich waters. Plants like Rhynia and Horneophyton stand in life position, with rhizoids still attached. Soft tissues such as parenchyma survive here when elsewhere they are lost. The site reveals how early plants branched, repaired wounds, and took up water. It offers a rare window into life on land long before forests existed.