# Eurotiomycetes

Eurotiomycetes is a large class of ascomycetes with cleistothecial ascocarps within the subphylum Pezizomycotina, currently containing around 3810 species according to the Catalogue of Life. It is the third largest lichenized class, with more than 1200 lichen species that are mostly bitunicate in the formation of asci. It contains most of the fungi previously known morphologically as "Plectomycetes".

## Systematics and phylogeny
### Internal relationships

The class Eurotiomycetes was circumscribed in 1997 by Swedish mycologists Ove Erik Eriksson and Katarina Winka. At that time it only contained the order Eurotiales, which together with the next order added, Onygenales, form a monophyletic group comprising most of the fungi in "Plectomycetes", a group no longer in use that unified fungi under exclusively morphological characteristics.
As more orders were added to Eurotiomycetes, the first two along with Arachnomycetales became constrained to the first subclass, Eurotiomycetidae. In 2001, the second subclass, Chaetothyriomycetidae, was erected to accommodate Chaetothyriales and its sister group Verrucariales, as well as Pyrenulales since 2004. These two remain as the major subclasses of Eurotiomycetes.
The remaining subclasses were created through more phylogenetic analyses to accommodate outlying taxa or newly discovered groups: Mycocaliciomycetidae in 2007, Coryneliomycetidae and Sclerococcomycetidae in 2016, and lastly Cryptocaliciomycetidae in 2021. The following cladogram shows the relationships between all Eurotiomycetes orders and monotypic subclasses as of 2021:

### External relationships

The class Eurotiomycetes forms a clade with Lecanoromycetes, the largest lichenized class of fungi.

## Taxonomy

As of 2022, the taxonomy of Eurotiomycetes recognizes 5 subclasses, 10 orders, 34 families and 289 valid genera. The families are listed here followed by the number of genera.
    Subclass Chaetothyriomycetidae Doweld 2001
       Order Chaetothyriales M.E. Barr 1987
          Family Chaetothyriaceae Hansf. ex M.E. Barr 1979 – 19 genera
          Family Coccodiniaceae Höhn. ex O.E. Erikss. – 4 genera
          Family Cyphellophoraceae Réblová & Unter. – 2 genera
          Family Epibryaceae S. Stenroos & Gueidan – 1 genus
          Family Herpotrichiellaceae Munk – 17 genera
          Family Lyrommataceae Lücking – 1 genus
          Family Microtheliopsidaceae O.E. Erikss. – 1 genus
          Family Paracladophialophoraceae Crous – 1 genus
          Family Pyrenotrichaceae Zahlbr – 2 genera
          Family Trichomeriaceae Chomnunti & K.D. Hyde (=Strelitzianaceae Crous & M.J. Wingf.) – 9 genera
          Chaetothyriales incertae sedis – 11 genera
       Order Phaeomoniellales K.H. Chen, A.E. Arnold, Gueidan & Lutzoni
          Family Celotheliaceae Lücking, Aptroot & Sipman (=Phaeomoniellaceae P.M. Kirk) – 11 genera
       Order Pyrenulales Fink ex D. Hawksw. & O.E. Erikss.
          Family Pyrenulaceae Rabenh. – 12 genera
          Pyrenulales incertae sedis – 2 genera
       Order Verrucariales Mattick ex D. Hawksw. & O.E. Erikss.
          Family Adelococcaceae Triebel – 3 genera
          Family Sarcopyreniaceae Nav.-Ros. & Cl. Roux – 1 genera
          Family Verrucariaceae Zenker – 52 genera
          Verrucariales incertae sedis – 4 genera
       Chaetothyriomycetidae incertae sedis
          Family Rhynchostomataceae Winka & O.E. Erikss. – 2 genera
    Subclass Cryptocaliciomycetidae M. Prieto, Etayo and Olariaga 2021
       Order Cryptocaliciales M. Prieto, Etayo and Olariaga 2021
          Family Cryptocaliciaceae Etayo, Olariaga and M. Prieto – 1 genus
    Subclass Coryneliomycetidae A.R. Wood, Damm, J.Z. Groenew., Cheew. & Crous
       Order Coryneliales Seaver & Chardon
          Family Coryneliaceae Sacc. ex Berl. & Voglino – 8 genera
          Family Eremascaceae Engl. & E. Gilg – 2 genera
    Subclass Eurotiomycetidae Geiser & Lutzoni
       Order Arachnomycetales Gibas, Sigler & Currah
          Family Arachnomycetaceae Gibas, Sigler & Currah – 2 genera
       Order Eurotiales G.W. Martin ex Benny & Kimbr.
          Family Aspergillaceae Link (=Monascaceae J. Schröt.) – 14 genera
          Family Elaphomycetaceae Tul. ex Paol. – 2 genera
          Family Penicillaginaceae Houbraken, Frisvad & Samson – 1 genus
          Family Thermoascaceae Apinis – 2 genera
          Family Trichocomaceae E. Fisch. – 9 genera
       Order Onygenales Cif. ex Benny & Kimbr.
          Family Ajellomycetaceae Unter., J.A. Scott & Sigler – 7 genera
          Family Arthrodermataceae Currah – 11 genera
          Family Ascosphaeraceae L.S. Olive & Spiltoir – 3 genera
          Family Gymnoascaceae Baran. – 11 genera
          Family Nannizziopsidaceae Guarro, Stchigel, Deanna A. Sutton & Cano – 1 genus
          Family Onygenaceae Berk. – 34 genera
          Family Spiromastigaceae Guarro, Cano & Stchigel – 4 genera
          Onygenales incertae sedis – 3 genera
       Eurotiomycetidae incertae sedis – 5 genera
    Subclass Mycocaliciomycetidae Tibell
       Order Mycocaliciales Tibell & Wedin
          Family Mycocaliciaceae A.F.W. Schmidt (=Sphinctrinaceae M. Choisy) – 7 genera
    Subclass Sclerococcomycetidae Réblová, Unter. & W. Gams
       Order Sclerococcales Réblová, Unter. & W. Gams
          Family Dactylosporaceae Bellem. & Hafellner (=Sclerococcaceae Réblová, Unter. & W. Gams) – 7 genera
Only one genus, Neocladophialophora, remains incertae sedis within the class.

## Nomenclature

The scientific classification for this particular class is particularly tricky, with one particular species having both the anamorph (asexual form), and teleomorph (sexual form) names used in reference to them.
* e.g. anamorph form = Penicillium; teleomorph form = Talaromyces or Eupenicillium.

## Morphology

Many members (Eurotiales, Onygenales) produce an enclosed structure cleistothecium within which they produce their spores.