Phylum Ascomycota Caval.-Sm. (1998) - sac fungi Subphylum Taphrinomycotina O.E. Erikss. & Winka (1997) - basal ascomycetes Class Schizosaccharomycetes O.E. Erikss. & Winka (1997) - fission yeasts Order Schizosaccharomycetales O.E. Erikss. et al. (1993)