[3] The genus was circumscribed in 1983 by the Austrian mycologist Josef Hafellner, with Lichenostigma maureri assigned as the type species.

Discoveries from European Paleogene amber have identified two fossil specimens of Lichenostigma associated with the crustose lichen genus Ochrolechia.

The presence of Lichenostigma in these amber inclusions confirms that both the genus and its specialised parasitic association with Ochrolechia were already well-established during this period.

The fossilised Lichenostigma specimens have conidiomata and ascomata (specialised structures to produce asexual and sexual spores, respectively) that are morphologically similar to those of modern species, demonstrating the evolutionary continuity of these lichenicolous fungi.

This discovery not only pushes back the minimum age of the genus Lichenostigma but also provides calibration points for phylogenetic studies.