Phylogenetic analyses of strains from an aquatic environment, including LSU, SSU and rpb2 sequence data, grouped them in a monophyletic clade with Achroceratosphaeria species (Réblová et al. 2015a). The new taxa were placed in the novel genus, Pisorisporium and a new family, Pisorisporiaceae was erected to accommodate Pisorisporium and Achroceratosphaeria. The latter genus was, upon its introduction, initially placed in Sordariomycetes incertae sedis (Réblová et al. 2010). This new family Pisorisporiaceae was, in turn, accommodated in Pisorisporiales based on its distinct taxonomy and phylogeny at the ordinal level (Réblová et al. 2015a). Pisorisporiales forms a
moderately-supported sister clade with Lulworthiales and Koralionastetales in Lulworthiomycetidae (Hongsanan et al. 2017). The order has been reported to have a stem age which falls between 250–300 MYA, thereby placing it at a subclass level (Hyde et al. 2017a, Hongsanan et al. 2017). In this study, therefore Pisorisporiales is raised to the subclass Pisorisporiomycetidae. Currently there is one family and two genera in this order (Hyde et al. 2020).