Belongs within: Dothideomyceta.
The Microthyriaceae are a family of saprobic or epiphytic fungi with strongly flattened, superficial ascomata (Kirk et al. 2001).
Characters (Kirk et al. 2001): Superficial mycelium indistinct. Ascomata small, strongly flattened, superficial, with small central ostiole sometimes surrounded by thickened tissue; peridium brown, composed of radiating rows of irregular, epidermoid or more or less isodiametric cells, basal layer hyaline, poorly developed or absent. Interascal tissue of trabeculate pseudoparaphyses, often deliquescing. Asci saccate, fissitunicate, without a clear ocular chamber, not blueing in iodine. Ascospores hyaline or brown, transversely septate, sometimes ciliate, without a sheath.
<==Microthyriaceae [Trichopeltaceae, Trichothyriaceae]
|--Actinomyxa Syd. & Syd. 1917KC01
|--Asterinema Bat. & Gayão 1953KC01
|--Asteritea Bat. & Garnier 1961KC01
|--Asteronia (Sacc.) Henn. 1895KC01
|--Byssopeltis Bat., Bezerra & Barros 1970KC01
|--Calothyriopsis Höhn. 1919 [incl. Ptychopeltis Syd. 1927 non Perner 1903 (ICZN)]KC01
|--Caribaeomyces Cif. 1962KC01
|--Caudella Syd. & Syd. 1916KC01
|--Cirsosina Bat. & Bezerra 1960KC01
|--Cirsosiopsis Butin & Speer 1979KC01
|--Dictyoasterina Hansf. 1947KC01
|--Govindua Bat. & Maia 1960KC01
|--Helminthopeltis Sousa da Câmara 1950KC01
|--Hidakaea Hino & Katum. 1955KC01
|--Lembosiella Sacc. 1891KC01
|--Lichenopeltella Höhn. 1919 (see below ofr synonymy)KC01
|--Microthyrium Desm. 1841 [incl. Calothyriella Höhn. 1917, Microthyrina Bat. 1960, Phragmothyrium Höhn. 1912]KC01
|--Muyocopron Spegazzini 1881KC01 (see below for synonymy)
|--Pachythyrium Arnaud ex Spooner & Kirk 1990KC01
|--Palawania Syd. & Syd. 1914KC01
|--Petrakiopeltis Bat., Vital & Cif. 1957KC01
|--Phaeothyriolum Syd. 1938KC01
|--Phragmaspidium Bat. 1960KC01
|--Platypeltella Petr. 1929 [incl. Asterinopeltis Bat. & Maia 1958]KC01
|--Polycyclinopsis Bat., Vital & Lima 1958KC01
|--Resendea Bat. 1961KC01
|--Sapucchaka Ramakr. 1956KC01
|--Scolecopeltidium Stevens & Manter 1925 [=Scolecopeltium Clem. & Shear 1931]KC01
|--Seynesiella Arnaud 1918KC01
|--Seynesiopeltis Stevens & Ryan 1925KC01
|--Stegothyrium Höhn. 1918KC01
|--Tothia Bat. 1960KC01
|--Trichopeltella Höhn. 1910 [=Raciborskiella Spegazzini 1919 non von Höhnel 1909]KC01
|--Trichopeltina Theiss. 1914KC01
|--Trichopeltospora Bat. & Cif. 1958KC01
|--Trichopeltum Bat., Cif. & Costa 1958KC01
|--Trichothyriella Theiss. 1914KC01
|--Trichothyrinula Petr. 1950KC01
|--Trichothyriomyces Bat. & Maia 1955KC01
|--Trichothyriopsis Theiss. 1914KC01
|--Xenostomella Syd. 1930 [incl. Plochmothea Syd. 1939]KC01
|--Trichopeltinites Cookson 1947T93, KC01
|--Actinopeltis Höhn. 1907 (see below for synonymy)KC01
| `--‘Loranthomyces’ sordidulus (Lév.) v. Hoehn. 1909SS16
|--Arnaudiella Petr. 1927 non Douvillé 1907 (ICZN) [incl. Seynesiola Speg. 1919]KC01
|--Callimothallus Dilcher ex Janson. & Hillis 1977KC01
|--Cyclotheca Theiss. 1914 (see below for synonymy)KC01
|--Maublancia Arnaud 1918 [incl. Caudellopeltis Bat. & Maia 1960]KC01
|--Corynocladus Leidy 1850 (n. d.)KC01
|--Cribrites Lange 1978KC01
|--Hugueninia Bezerra & Barros 1970KC01
|--Mariusia Pons & Boureau 1977KC01
|--Microthallites Dilcher 1965KC01
|--Microthyriacites Cookson 1947KC01
| `--M. grandisPR04
|--Monorhizina Theiss. & Syd. 1915KC01
|--Notothyrites Cookson 1947KC01
|--Paramicrothallites Jain & Gupta 1970KC01
|--Parmathyrites Jain & Gupta 1970KC01
|--Pelicothallos Dilcher 1965KC01
|--Polystomellina Bat. & Vital 1958 non Yabe & Hanzawa 1923 (ICZN)KC01
|--Asterinella Theiss. 1912 [incl. Calothyrium Theiss. 1912, Opasterinella Speg. 1917]KC01
| `--A. tecleaeDP72
|--Trichothyrium Speg. 1889 (see below for synonymy)KC01
| `--T. asterophorumDP72
`--Phragmothyrites Edwards 1922PR04, KC01
`--P. concentricus Phipps & Rember 2004PR04
Actinopeltis Höhn. 1907 non Hawle & Corda 1847 (ICZN) [incl. Actinopeltella Doidge 1924, Actinosoma Syd. 1930, Asteridiellina Seaver & Toro 1926, Caenothyrium Theiss. & Syd. 1918, Chaetothyriopsis Stevens & Dorman 1927, Dasypyrena Speg. 1912, Halbaniella Theiss. 1917, Loranthomyces Höhn. 1909, Mycolangloisia Arnaud 1918, Trotteria Sacc. 1919]KC01
Cyclotheca Theiss. 1914 [incl. Calopeltis Syd. 1925, Hariotula Arnaud 1917, Seynesiospora Bat. 1960, Synostomella Syd. 1927, Synpeltis Syd. & Syd. 1917, Thyrosoma Syd. 1921]KC01
Lichenopeltella Höhn. 1919 [=Microthyris Clem. 1931 nec Lederer 1863 (ICZN) nec Eudes-Deslongchamps 1884 (ICZN); incl. Micropeltopsis Vain. 1921, Trichothyrina (Petr.) Petr. 1950]KC01
Muyocopron Spegazzini 1881KC01 [incl. Ellisiodothis Theissen 1914KC01, Haplopeltis Theissen 1914KC01, Myiocopron Spegazzini 1881PR04, Peltella Syd. & Syd. 1917 non Gray 1855 (ICZN)KC01, Peltopsis Bat. 1960KC01]
Trichothyrium Speg. 1889 [incl. Carlosia Arnaud 1954 non Samp. 1923, Hansfordiella Hughes 1951, Isthmospora Stevens 1918, Trichopeltis Speg. 1889, Trichopeltopsis Höhn. 1909, Trichopeltula Theiss. 1914]KC01
*Type species of generic name indicated
References
[DP72] Deighton, F. C., & K. A. Pirozynski. 1972. Microfungi. V. More hyperparasitic hyphomycetes. Mycological Papers 128: 1–110.
[KC01] Kirk, P. M., P. F. Cannon, J. C. David & J. A. Stalpers. 2001. Ainsworth & Bisby’s Dictionary of the Fungi 9th ed. CAB International: Wallingford (UK).
[PR04] Phipps, C. J., & W. C. Rember. 2004. Epiphyllous fungi from the Miocene of Clarkia, Idaho: reproductive structures. Review of Palaeobotany and Palynology 129 (1-2): 67–79.
[SS16] Sydow, H., & P. Sydow. 1916. Fungi papuani. Die von C. Ledermann in Neu-Guinea gesammelten Pilze. Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 54: 246–261.
[T93] Taylor, T. N. 1993. Fungi. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 9–13. Chapman & Hall: London.