Phylogenetic analyses of nucleotide data from the ITS and 5.8S rDNA gene region were performed on 37 strains of Onygenales representing all the accepted species of Auxarthron (9 strains), several species of Amauroascus (16 strains), and morphologically similar genera (3 strains of Amaurascopsis, 1 of Apinisia, 1 of Shanorella, 1 of Mallochia, 2 of Nannizziopsis, 1 of Pectinotrichum, and 3 of Uncinocarpus). The inferred phylogeny provided strong support for the monophyly of Auxarthron. We propose the new combinations Auxarthron kuehnii and A. pseudoreticulatum combs nov. and provide a key to the accepted species of Auxarthron. Although this study demonstrated that Amauroascus is polyphyletic, relationships among the members of that genus could not be resolved in phylogenies inferred from the analyses of ITS sequences; the new combination A. queenslandicus comb. nov. is also proposed. Molecular data suggested that Amaurascopsis reticulatus, characterised by the absence of discrete ascomata and prominently echinulate ascospores, can be accomodated in Mallochia.