Phylum Ascomycota Caval.-Sm. (1998) - sac fungi
   Subphylum Pezizomycotina O.E. Erikss. & Winka (1997)
     Class Eurotiomycetes O.E. Erikss. & Winka (1997)
       Subclass Chaetothyriomycetidae Doweld (2001)
         Order Pyrenulales Fink ex D.Hawksw. & O.E. Erikss. (1986)
           1 Family Pyrenulaceae Rabenh. (1870)
           2 Genus Heufleridium Müll.Arg. (1883), incertae sedis
           3 Genus Rhaphidicyrtis Vain. (1921), incertae sedis
           4 Genus Rhexoampullifera P.M.Kirk (1982), incertae sedis
           5 Genus Stromatothelium Trevis. (1861), incertae sedis
           6 Genus Xenus Kohlm. & Volkm.-Kohlm. (1992), incertae sedis