The family Sporormiaceae (Pleosporales, Dothideomycetes, Ascomycota) occur worldwide and a majority of the species are coprophilous. The taxonomy and classification of the family are based on a small number of morphological and ecological characters. Several taxa are easily confused by their shared morphological features, and the relationships between genera are poorly known and in need of critical study. The aims of this study were to resolve the phylogenetic relationships within the Sporormiaceae, test the current generic classification, and study the utility of traditional characters for the taxonomy in the group. To resolve these questions, we analysed combined data sets of ITS-nLSU rDNA, mtSSU rDNA and ß-tubulin sequences with parsimony and Bayesian methods.
The results showed that many characters, which previously have been used in the taxonomy and classification of the Sporormiaceae, such as the substrate choice, presence or absence of an ostiole, and presence or absence of germ slits, were all homoplastic and not useful for circumscribing monophyletic groups. A number of characters may be useful for circumscribing smaller clades if used in combination with other features, such as the shape of the ascus with the shape of the ascospores. Our phylogenetic analyses show that Preussia and Sporormiella are non-monophyletic, and a constrained analysis forcing these genera into monophyly resulted in significantly worse trees. Spororminula is nested in Preussia s. lat., and Eremodothis and Pycnidiophora are nested within Westerdykella. Finally, we suggest a new generic classification for the family Sporormiaceae, including Sporormia, Preussia (including Sporomiella and Spororminula) and Westerdykella (including Eremodothis and Pycnidiophora). We also propose 14 new combinations: Preussia alloiomera (S.I. Ahmed & Cain) Kruys, Preussia antarctica (Speg.) Kruys, Preussia bipartis (Cain) Kruys, Preussia borealis (I.Egeland) Kruys, Preussia dubia (S.I. Ahmed & Cain) Kruys, Preussia lignicola (W. Phillips & Plowr.) Kruys, Preussia longisporopsis (S.I. Ahmed & Cain) Kruys, Preussia minipascua (S.I. Ahmed & Cain) Kruys, Preussia octomera (Auersw.) Kruys, Preussia splendens (Cain) Kruys, Preussia tenerifae (Arx & Aa) Kruys, Preussia tetramera (S.I. Ahmed & Cain) Kruys, Westerdykella angulata (A.C. Das) Kruys and Westerdykella aurantiaca (J.N. Rai & J.P. Tewari) Kruys.