Studies of fungi and fungal activities in fossil wood are relatively rare, although silicified wood is one of the most common plant fossils. Signs of fungal degradation are frequently encountered in fossil wood, and many fungus-affected woods contain also evidence of the causative agent in the form of hyphae, spores, etc. Documented evidence of late Devonian wood-fungus interactions is exceedingly sparse and limited to a few reports in Callixylon spp., a Devonian wood attributed to archaeopteridalean progymnosperms. This contribution provides new information and examples of fungi in Callixylon newberryi from the New Albany Shale, southern Indiana, USA, based on thin sections from a historical set of slides on loan from the University College Dublin, Ireland. It is unclear whether all thin sections were prepared from the same wood specimen, but there are abundant fungal remains in all slides. Based on the abundance of fungal remains in the C. newberryi samples, several distinct distribution patterns and interaction types can be reconstructed. This study provides a new data set for considerations on the coevolution between early woody plants and fungi that can be used in molecular clock calibrations and as proxies for (palaeo)ecosystem cycling and functioning.