The holotype of Thyronectria hyperantarctica was re-examined, redescribed, and compared with new collections of an Antarctic bryophilous ascomycete from a similar area. Because the condition of type material was insufficient for molecular studies, the authors designated an epitype from newly collected material with a high degree of morphological similarity to the holotype and paratype material. Phylogenetic analysis of the epitype revealed that its closest phylogenetic affinity was with the family Tilachlidiaceae and it formed a monophyletic group in this lineage within other collections of the species. Therefore, the new monotypic genus Psychronectria is described to accommodate Thyronectria hyperantarctica. The fungus is superficially similar to Thyronectria species in Nectriaceae, but the ascospores differ in color, size, and type of septation.
Keywords: Moss-associated fungus; Nectriaceae; Thyronectria; Tilachlidiaceae; taxonomy.