Holomycota or Nucletmycea are a basal

Opisthokont The opisthokonts () are a broad group of eukaryotes, including both the animal and fungus kingdoms. The opisthokonts, previously called the "Fungi/Metazoa group", are generally recognized as a clade. Opisthokonts together with Apusomonadida and ...

clade as

sister A sister is a woman or a girl who shares parents or a parent with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to ref ...

of the

Holozoa Holozoa () is a clade of organisms that includes animals and their closest single-celled relatives, but excludes fungi and all other organisms. Together they amount to more than 1.5 million species of purely heterotrophic organisms, including a ...

. It consists of the

Cristidiscoidea The nucleariids, or nucleariid amoebae, are a group of amoebae that compose the sister clade of the fungi. Together, they form the clade Holomycota. They are aquatic organisms found in freshwater and marine habitats, as well as in faeces. They a ...

and the kingdom

Fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

. The position of

nucleariids The nucleariids, or nucleariid amoebae, are a group of amoebae that compose the sister clade of the fungi. Together, they form the clade Holomycota. They are aquatic organisms found in freshwater and marine habitats, as well as in faeces. They a ...

, unicellular free-living phagotrophic amoebae, as the earliest lineage of Holomycota suggests that animals and

fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

independently acquired complex multicellularity from a common unicellular ancestor and that the osmotrophic lifestyle (one of the

fungal A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as one of the tradit ...

hallmarks) was originated later in the divergence of this

eukaryotic The eukaryotes ( ) constitute the Domain (biology), domain of Eukaryota or Eukarya, organisms whose Cell (biology), cells have a membrane-bound cell nucleus, nucleus. All animals, plants, Fungus, fungi, seaweeds, and many unicellular organisms ...

lineage. Opisthosporidians is a recently proposed taxonomic group that includes aphelids,

Microsporidia Microsporidia are a group of spore-forming unicellular parasites. These spores contain an extrusion apparatus that has a coiled polar tube ending in an anchoring disc at the apical part of the spore.Franzen, C. (2005). How do Microsporidia inva ...

and Cryptomycota, three groups of

endoparasites Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The ent ...

. '' Rozella'' ( Cryptomycota) is the earliest diverging

genus in which

chitin Chitin (carbon, C8hydrogen, H13oxygen, O5nitrogen, N)n ( ) is a long-chain polymer of N-Acetylglucosamine, ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is the second most abundant polysaccharide in nature (behind only cell ...

has been observed at least in some stages of their life cycle, although the chitinous

cell wall A cell wall is a structural layer that surrounds some Cell type, cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, ...

(another

hallmark) and

osmotrophy Osmotrophy is a form of heterotrophic nutrition and a cellular feeding mechanism involving the direct absorption of dissolved organic compounds by osmosis. Organisms that use osmotrophy are called osmotrophs. Osmotrophy is used by diverse groups o ...

originated in a common ancestor of

Blastocladiomycota Blastocladiomycota is one of the currently recognized phyla within the kingdom Fungi.Hibbett DS et al. 2007. A higher-level phylogenetic classification of the fungi. Mycological Research 111:509–47. Blastocladiomycota was originally the order ...

and

Chytridiomycota Chytridiomycota are a division of zoosporic organisms in the kingdom Fungi, informally known as chytrids. The name is derived from the Ancient Greek ('), meaning "little pot", describing the structure containing unreleased zoospores. Chytrid ...

, which still contain some ancestral characteristics such as the

flagellum A flagellum (; : flagella) (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cells, from fungal spores ( zoospores), and from a wide range of microorganisms to provide motility. Many pr ...

zoosporic A zoospore is a motile asexual spore In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of tim ...

stage. The groups of

with the characteristic

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one o ...

l growth, Zoopagomycota, Mucoromycotina and

Dikarya Dikarya is a subkingdom of Fungi that includes the divisions Ascomycota and Basidiomycota, both of which in general produce dikaryons, may be hypha, filamentous or unicellular, but are always without flagella. The Dikarya are most of the so-calle ...

, originated from a common ancestor ~700 Mya. Zoopagomycota are mostly pathogens of animals or other

, Mucoromycotina is a more diverse group including parasites, saprotrophs or ectomycorrhizal.

is the group embracing

Ascomycota Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The def ...

and

Basidiomycota Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basi ...

, which comprise ~98% of the described

species. Because of this rich diversity,

includes highly morphologically distinct groups, from

e or unicellular

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...

s (such as the model organism ''

Saccharomyces cerevisiae ''Saccharomyces cerevisiae'' () (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungal microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have be ...

'') to the complex multicellular

popularly known as mushrooms. Contrary to animals and land plants with complex multicellularity, the inferred phylogenetic relationships indicate that

acquired and lost multicellularity multiple times along

and

evolution.

Phylogeny

The

phylogenetic tree A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA. In ...

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.

References

{{Taxonbar, from=Q2943473 Opisthokont taxa