Excavata is a major supergroup of unicellular organisms belonging to the domain Eukaryota. Introduced by Thomas Cavalier-Smith in 2002 as a new phylogenetic category, it contains a variety of free-living and symbiotic forms, and also includes some important parasites of humans. Excavates were formerly considered to be included in the now obsolete Protista kingdom. They are classified based on their flagellar structures, and they are considered to be the most basal Flagellate lineage.
The Cercozoa are a group of single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, being defined by molecular phylogenies of rRNA and actin or polyubiquitin.
The Rhizaria are a species-rich supergroup of mostly unicellular eukaryotes. A multicellular form has also been described. This supergroup was proposed by Cavalier-Smith in 2002. Being described mainly from rDNA sequences, they vary considerably in form, having no clear morphological distinctive characters (synapomorphies), but for the most part they are amoeboids with filose, reticulose, or microtubule-supported pseudopods. Many produce shells or skeletons, which may be quite complex in structure, and these make up the vast majority of protozoan fossils. Nearly all have mitochondria with tubular cristae.
Unikonts or Amorphea are members of 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.
Ancyromonas is a basal Eukaryote. It is a flagellate.
Corticata, in the classification of eukaryotes, is a clade suggested by Cavalier-Smith to encompass the eukaryote supergroups of the following two groups:
Micronuclearia is a Nucleariid genus.
Endomyxa is a subphylum of Rhizaria.
Proteomyxidea is a class of Cercozoa. Although it is known to be paraphyletic, further research is needed before its classification can be improved.
Heliomorpha is a genus of Cercozoa, placed in its own family, Heliomorphidae. It used to be known as "Dimorpha", but that name was a junior synonym several times over.
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 layer teak and the mitochondrial crests are discoidal / flat.
The Archaeplastida+HC+SAR megagroup is a group of eukaryotes proposed by Burki et al. (2008).
Varisulca is a proposed basal Podiate taxon. It encompasses several lineages of heterotrophic protists, most notably the ancyromonads (planomonads), collodictyonids (diphylleids), rigifilids and Mantamonas. 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
Endohelea is a proposed clade of eukaryotes that are related to Archaeplastida and the SAR supergroup.
Obazoa is a proposed sister clade of Amoebozoa. Obazoa is composed of Breviatea, Apusomonadida and Opisthokonta, and specifically excludes the Amoebozoa. Determining the placement of Breviatea and Apusomonadida and their properties is of interest for the development of the opisthokonts in which the main lineages of animals and fungi emerged. The relationships among opisthokonts, breviates and apusomonads are not conclusively resolved, though Breviatea is usually inferred to be the most basal of the three lineages. Ribosomal RNA phylogenies do not usually recover Obazoa as a clade, probably reflecting their stemming from a very ancient common ancestor, and little phylogenetic signal remains in datasets consisting of one or a few genes.
Corbihelia is a phylum of eukaryotes.
The Orthokaryotes are a proposed Eukaryote clade consisting of the Jakobea and the Neokaryotes. Together with its sister Discicristata it forms a basal Eukaryote clade. They are characterized by stacked Golgi, orthogonal centrioles, and two opposite posterior ciliary roots.
The neokaryotes are a proposed eukaryote clade consisting of the unikonts and the bikonts as sister of for instance the Jakobea. It arises because the Euglenozoa, Percolozoa, Tsukubea, and Jakobea are seen in this view as more basal eukaryotes. These four groups, are traditionally grouped together in the Discoba. However, the Discoba may well be paraphyletic as the neokaryotes may have emerged in them.
The Scotokaryotes (Cavalier-Smith) or Opimoda is a proposed basal Neokaryote clade as sister of the Diaphoratickes. Basal Scotokaryote groupings are the Metamonads, the Malawimonas and the Podiata. The Discoba are sometimes seen as paraphyletic and basal Eukaryotes.
