Phylum Ascomycota Caval.-Sm. (1998) - sac fungi
   Subphylum Pezizomycotina O.E. Erikss. & Winka (1997)
     Class Lecanoromycetes O.E. Erikss. & Winka (1997)
       Subclass Ostropomycetidae V. Reeb, Lutzoni & Cl.Roux (2004)
         Order Ostropales Nannf. (1932)
           Family Graphidaceae Dumort. (1822)
             Genus Thalloloma Trevis. (1853)