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Twenty-six strains of black, mostly meristematic fungi isolated from cryptoendolithic lichen dominated communities in the Antarctic were described by light and Scanning Electron Microscopy and sequencing of the ITS rDNA region. In addition, cultural and temperature preferences were investigated. The phylogenetic positions of species recognised were determined by SSU rDNA sequencing. Most species showed affinity to the Dothideomycefidae and constitute two main groups referred to under the generic names Friedmanniomyces and Cryomyces (gen. nov.), each characterised by a clearly distinct morphology. Two species could be distinguished in each of these genera. Six strains could not be assigned to any taxonomic group; among them strain CCFEE 457 belongs to the Hysteriales, clustering together with Mediterranean marble-inhabiting Coniosporium species in an approximate group with low bootstrap support. All strains proved to be psychrophiles with the only exception for the strain CCFEE 507 that seems to be mesophilic-psychrotolerant. All had very thick melanised cell walls, the ability to produce exopolysaccharides and to grow meristematically. They are thought to be well adapted to the harsh environment of the Antarctic cold Desert. Hypotheses concerning their origin and evolution are put forward.