[1][2] The genus, as circumscribed by Rossman et al. (1998), included all the nectrioid species with small, reddish, non-ornamented sexual fruiting bodies that collapse laterally when dry.

[1] However, the genus was shown to be polyphyletic,[3] and the majority of species were re-classified into revived or recently established genera that are monophyletic.

[3][4] Cosmospora sensu Rossman housed members of the following genera: Chaetopsina, Cylindrocladiella, Fusicolla, Macroconia, Mariannaea, Microcera, Pseudocosmospora, Stylonectria, and Volutella.

[2] Cosmospora was restricted to species having acremonium-like asexual morphs that grow on polypores and xylariaceous fungi by Gräfenhan in 2011.

Cosmospora Chaetopsina Cylindrocladiella Dialonectria Fusicolla Macroconia Mariannaea Microcera Pseudocosmospora Stylonectria Volutella Incertae sedis