Holomycota or Nucletmycea are a basalOpisthokont clade as sister of the Holozoa. It consists of the Cristidiscoidea and the kingdom Fungi. The position of nucleariids, unicellular free-living phagotrophic amoebae, as the earliest lineage of Holomycota suggests that animals and fungi independently acquired complex multicellularity from a common unicellular ancestor and that the osmotrophic lifestyle was originated later in the divergence of this eukaryotic lineage. Opisthosporidians is a recently proposed taxonomic group that includes aphelids, Microsporidia and Cryptomycota, three groups of endoparasites. Rozella is the earliest fungal genus in which chitin has been observed at least in some stages of their life cycle, although the chitinus cell wall and osmotrophy originated in a common ancestor of Blastocladiomycota and Chytridiomycota, which still contain some ancestral characteristics such as the flagellum in zoosporic stage. The groups of fungi with the characteristic hyphal growth, Zoopagomycota, Mucuromycotina and Dikarya, originated from a common ancestor ~700 Mya. Zoopagomycota are mostly pathogens of animals or other fungi, Mucuromycotina is a more diverse group including parasites, saprotrophs or ectomycorrhizal. Dikarya is the group embracingAscomycota and Basidiomycota, which comprise ~98% of the described fungal species. Because of this rich diversity, Dikarya includes highly morphologically distinct groups, from hyphae or unicellular yeasts to the complex multicellular fungi popularly known as mushrooms. Contrary to animals and land plants with complex multicellularity, the inferred phylogenetic relationships indicate that fungi acquired and lost multicellularity multiple times along Ascomycota and Basidiomycota evolution.
Phylogeny
The phylogenetic tree depicts the fungi and their close relationship to other organisms, based on the work of Philippe Silar and "The Mycota: A Comprehensive Treatise on Fungi as Experimental Systems for Basic and Applied Research". The holomycota tree is following Tedersoo et al.
