Ancient Basidiomycota in an extinct conifer-like tree, <i>Xenoxylon utahense</i>, and a brief survey of fungi in the Upper Jurassic Morrison Formation, USA

Abstract Although the well-known Upper Jurassic Morrison Formation has yielded abundant fossil plants for nearly a century, relatively little is known about fungi and their ecological relationships to flora. The first mention of fungal decay in wood was briefly made over three decades ago, since then, few more reports associated with have been published. However, up now, detailed data on themselves not given from Formation. Here we describe detail well-preserved mycelia silicified log Xenoxylon utahense Xie et Gee, 2021 at Miners Draw, Blue Mountain, near Vernal northeastern Utah, USA. hyphae are variable form, ranging straight slightly curved highly coiled tubular; they measure ~1.53 μm diameter possess clamp connections, septa, occasional bifurcations. occurrence connections typical living Basidiomycota indicates taxonomic affinity this division fungi. On basis patterns log, interpreted here as pertaining saprotrophic, white-rot These represent new record ancient provide further evidence plant–fungus interactions terrestrial ecosystems.