Excavata is an extensive and diverse but paraphyletic group of unicellular Eukaryota. The group was first suggested by Simpson and Patterson in 1999 and the name latinized and assigned a rank by Thomas Cavalier-Smith in 2002. It contains a variety of free-living and symbiotic protists, and includes some important parasites of humans such as Giardia and Trichomonas. Excavates were formerly considered to be included in the now obsolete Protista kingdom. They were distinguished from other lineages based on electron-microscopic information about how the cells are arranged. They are considered to be a basal flagellate lineage.
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 Breviata comprise the larger clade Obazoa.
Amorphea is a taxonomic supergroup that includes the basal Amoebozoa and Obazoa. That latter contains the Opisthokonta, which includes the Fungi, Animals and the Choanomonada, or Choanoflagellates. The taxonomic affinities of the members of this clade were originally described and proposed by Thomas Cavalier-Smith in 2002.
The Apusozoa are a paraphyletic phylum of flagellate eukaryotes. They are usually around 5–20 μm in size, and occur in soils and aquatic habitats, where they feed on bacteria. They are grouped together based on the presence of an organic shell or theca under the dorsal surface of the cell.
Malawimonadidae is a family of unicellular eukaryotes of outsize importance in understanding eukaryote phylogeny.
Breviata anathema is a single-celled flagellate amoeboid eukaryote, previously studied under the name Mastigamoeba invertens. The cell lacks mitochondria, much like the pelobionts to which the species was previously assigned, but has remnant mitochondrial genes, and possesses an organelle believed to be a modified anaerobic mitochondrion, similar to the mitosomes and hydrogenosomes found in other eukaryotes that live in low-oxygen environments.
Loukozoa is a proposed taxon used in some classifications of eukaryotes, consisting of the Metamonada and Malawimonadea. Ancyromonads are closely related to this group, as sister of the entire group, or as sister of the Metamonada. Amorphea may have emerged in this grouping, specifically as sister of the Malawimonads.
SAR or Harosa is a highly diverse clade of eukaryotes, often considered a supergroup, that includes stramenopiles (heterokonts), alveolates, and rhizarians. It is a node-based taxon, including all descendants of the three groups' last common ancestor, and comprises most of the now-rejected Chromalveolata. Their sister group has been found to be telonemids, with which they make up the TSAR clade.
The apusomonads are a group of protozoan zooflagellates that glide on surfaces, and mostly consume prokaryotes. They are of particular evolutionary interest because they appear to be the sister group to the Opisthokonts, the clade that includes both animals and fungi. Together with the Breviatea, these form the Obazoa clade.
Ancyromonadida or Planomonadida is a small group of biflagellated protists found in the soil and in aquatic habitats, where they feed on bacteria. Includes freshwater or marine organisms, benthic, dorsoventrally compressed and with two unequal flagellae, each emerging from a separate pocket. The apical anterior flagellum can be very thin or end in the cell membrane, while the posterior flagellum is long and is inserted ventrally or laterally. The cell membrane is supported by a thin single-layered theca and the mitochondrial crests are discoidal/flat.
Diaphoretickes is a major group of eukaryotic organisms, with over 400,000 species. The majority of the earth's biomass that carries out photosynthesis belongs to Diaphoretickes.
Breviatea, commonly known as breviate amoebae, are a group of free-living, amitochondriate protists with uncertain phylogenetic position. They are biflagellate, and can live in anaerobic (oxygen-free) environments. They are currently placed in the Obazoa clade. They likely do not possess vinculin proteins. Their metabolism relies on fermentative production of ATP as an adaptation to their low-oxygen environment.
Podiates are a proposed clade containing the Amorphea and the organisms now assigned to the clade CRuMs. Ancyromonadida does not appear to have emerged in this grouping. Sarcomastigota is a proposed subkingdom that includes all the podiates that are not animals or fungi. Sulcozoa is a proposed phylum within Sarcomastigota that does not include the phyla Amoebozoa (clade) and Choanozoa (paraphyletic), i.e. it includes the proposed subphyla Apusozoa and Varisulca
Varisulca was a proposed basal Podiate taxon. It encompassed several lineages of heterotrophic protists, most notably the ancyromonads (planomonads), collodictyonids (diphylleids), rigifilids and mantamonadids. Recent evidence suggests that the latter three are closely related to each other, forming a clade called CRuMs, but that this is unlikely to be specifically related to ancyromonads.
Cryptista is a clade of alga-like eukaryotes. It is most likely related to Archaeplastida which includes plants and many algae, within the larger group Diaphoretickes.
Mantamonads are a group of free-living heterotrophic flagellates that move primarily by gliding on surfaces. They are classified as one genus Mantamonas in the monotypic family Mantamonadidae, order Mantamonadida and class Glissodiscea. Previously, they were classified in Apusozoa as sister of the Apusomonadida on the basis of rRNA analyses. However, mantamonads are currently placed in CRuMs on the basis of phylogenomic analyses that identify their closest relatives as the Diphylleida and Rigifilida.
CRuMs or Crumalia is a proposed clade of microbial eukaryotes, whose name is an acronym of the following constituent groups: i) collodictyonids also known as diphylleids, ii) rigifilids and iii) mantamonadids as sister of the Amorphea. It more or less supersedes Varisulca, as Ancyromonadida are inferred not to be specifically related to the orders Diphylleida/Collodictyonida, Rigifilida and Mantamonadida.
A supergroup, in evolutionary biology, is a large group of organisms that share one common ancestor and have important defining characteristics. It is an informal, mostly arbitrary rank in biological taxonomy that is often greater than phylum or kingdom, although some supergroups are also treated as phyla.
Malawimonads are a small group of microorganisms with a basal position in the evolutionary tree of eukaryotes, containing only three recognized species. They're considered part of a paraphyletic group known as "Excavata".
Evosea is a diverse clade of amoeboid protists discovered through molecular analyses. Along with Tubulinea and Discosea, Evosea is one of the three major groups within Amoebozoa, an important clade of eukaryotic organisms. It contains unicellular organisms that display a wide variety of life cycles and cell shapes, including amoebae, flagellates and different kinds of slime molds.
