Classes and phyla of the kingdom Fungi.

Fungi are one of the most diverse groups of organisms with an estimated number of species in the range of 2–3 million. The higher-level ranking of fungi has been discussed in the framework of molecular phylogenetics since Hibbett et al., and the definition and the higher ranks (e.g., phyla) of the ‘true fungi’ have been revised in several subsequent publications. Rapid accumulation of novel genomic data and the advancements in phylogenetics now facilitate a robust and precise foundation for the higher-level classification within the kingdom. This study provides an updated classification of the kingdom , drawing upon a comprehensive phylogenomic analysis of , with which we outline well-supported nodes of the fungal tree and explore more contentious groupings. We accept 19 phyla of viz , , , , , , , , , , , , , , , , , and . In the phylogenies, resides in ; thus, the former is regarded as a synonym of the latter, while is viewed as a class in . We provide a description of each phylum followed by its classes. A new subphylum, Karpov is introduced as the only subphylum in . The subclass Kirk et al. in , is invalid and thus validated. Placements of fossil fungi in phyla and classes are also discussed, providing examples.