Abstract
The genus Thyridium has undergone significant taxonomic revision in recent years, including the incorporation of Phialemoniopsis and the establishment of the order Thyridiales. During a recent survey of coprophilous fungi in South Korea, we isolated a distinctive ascomycete from Hanwoo cattle feces that exhibited unique morphological and physiological traits. An integrative taxonomic approach combining morphological, physiological, and molecular evidence supports its recognition as a novel species. Multilocus phylogenetic analyses based on concatenated sequences (internal transcribed spacer (ITS), large subunit nuclear (LSU), β-tubulin, and actin) placed the new species within a monophyletic clade in Thyridium, distinct from all previously described taxa, with strong support values. Morphologically, T. intestinalis is characterized by flamingo-pink colonies on potato dextrose agar (PDA), distinctive branching patterns of conidiophores, and oval to cylindrical conidia, distinguishing it from closely related species. Physiologically, it exhibits a distinctive enzymatic profile with strong esterase (C4), leucine arylamidase, and N-acetyl-β-glucosaminidase activities. This study represents the first report of Thyridium from coprophilous habitats in East Asia, significantly expanding our understanding of the ecological plasticity and host associations. The enzymatic activity of T. intestinalis may shed light on its adaptation to herbivore-associated environments and may indicate its potential relevance to biomass degradation.