Fungi developing on dung samples, from a wide range of locations and incubated in moist chambers, were recorded. Highly significant differences were found among the mycobiota of different dung types, from different latitudinal ranges, and collected at different seasons. Sheep, cattle, deer, rabbit, hare and grouse provided 86 % of the 425 samples. Highly significant differences in the community composition of the mycobiota of these six dung types were observed. Coprinus stercoreus was the commonest basidiomycete, and most frequent on sheep, cattle, deer and rabbit; C. miser was the only common species, of any taxonomic group, which showed no significant difference in its frequency on different dungs. Apothecial fungi comprised about a quarter of the records, with Ascobolus, Saccobolus and Thelebolus spp., Iodophanus carneus and Lasiobolus cuniculi the commonest. A. carletonii occurred uniquely, but frequently, on grouse. Perithecial species, especially of Schizothecium, Podospora, Coniochaeta and Sporormiella, accounted for ca 50% of all records. The grouse dung mycobiota was markedly different, with a lower species richness (mean 3.2 per sample), from that of the mammalian herbivores, which had means of 9–12 spp. per sample. In temperate latitudes more species were recorded on samples in winter. Species richness was greater in samples from lower latitudes. Significant differences in the composition of different dung types are discussed in relation to their fungal communities. The usefulness of studying the fungi of the dung microcosm as a means of rapid biodiversity assessment is considered, by comparing the results with those of a similar, but smaller, study 30 years earlier, and by examining the diversity of a sample from a subjectively poor habitat in Morocco. There was no indication of any major change in the coprophilous mycobiota that might be associated, e.g. with climatic change or changed farming practice over the last three decades. The Moroccan samples had a much lower diversity (80 spp./50 samples) than would be expected of samples from that latitude (146 spp./50 samples) based on the worldwide data set.