The last two decades have been marked by the discovery of many Basidiomycota (fungi) who gain their nutrients from other fungi. This strategy is called mycoparasitism. Many of these fungi were found to represent very old lineages, having evolved early when Basidiomycota diverged from Ascomycota. However, for most of these species, relevant data to interpret the evolutionary patterns and importance of mycoparasitism is lacking. In this project, forces are bundled with European specialists to generate and compile this data and enlighten the evolutionary history of mycoparasitism and associated characters. These include specialized cells and organelles for interfungal interaction (haustoria and colacosomes resp.) and the phenomenon where a mycoparasite grows inside its host (indicated as intrahymenial growth). Therefore, specialized culture- and DNA extraction methods and electron microscopy will be applied. Further, genome sequences of these mycoparasites will be obtained and analysed to identify mycoparasitism related genes and to evaluate how they compare to those of closely related plant parasites. This will allow better understanding of the evolution and early diversification of Basidiomycota and may offer future perspectives for biocontrol of (crop) pathogenic fungi as these could be targeted by mycoparasites.