Abstract
Wood decomposition through fungal activity is essential to the natural carbon cycle. There are three primary patterns of wood decay: white rot, brown rot, and soft rot. However, geological records of wood decay mainly originate from fossil woods, which exclusively describe white rot before the Cenozoic. Fossilized charcoal is another excellent medium for preserving pre-charring decay structures. In this study, we collected numerous charcoals from the upper Permian and observed multiple microstructures indicative of wood decay. The distinctive characteristics closely resemble the symptoms of contemporary wood-rotting types, including the removal of the middle lamella and channel-like lysis seen in white rot, shot-like holes and wavy cell walls in brown rot, and cavities within the secondary walls in soft rot. This study documents the early occurrences of multiple wood-rotting types during the Late Paleozoic and provides insights into the range of fungal metabolic strategies employed during this period.