Phylogenetic and structural studies in the Thelebolaceae (Ascomycota)

Several minute dung-inhabiting discomycetes have been classified in the family Thelebolaceae, which has traditionally been included in the order Pezizales. The non-operculate type-genus Thelebolus has recently been excluded from the Pezizales. The phylogenetic distribution of other genera associated with Thelebolaceae is still obscure. We have analysed ca. 580 bp from a variable part of the nuclear SSU rRNA gene from Ascozonus, Caccobius, Lasiobolus and Thecotheus, and compared these with ca. 1700 bp sequences from Thelebolus, Pleospora. Pezizales, Leotiales and Leotiales-related taxa. In the resulting trees. Ascozonus and Caccobius group with Thelebolus and the inoperculate discomycetes, Lasiobolus groups with Ascodesmis, and Thecotheus with Ascobolus within Pezizales. SEM pictures of fruit-bodies and ascus apices of Ascozonus, and ascospores from Thecotheus are presented to illustrate characteristic features of these taxa.