Obazoa (Brown et al., 2013)
is a proposed sister
clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...
of
Amoebozoa
Amoebozoa is a major taxonomic group containing about 2,400 described species of amoeboid protists, often possessing blunt, fingerlike, lobose pseudopods and tubular mitochondrial cristae. In traditional and currently no longer supported classi ...
(which together form
Amorphea). Obazoa is composed of
Breviatea
''Breviata anathema'' is a single-celled flagellate amoeboid eukaryote, previously studied under the name ''Mastigamoeba invertens''. The cell lacks mitochondria but has remnant mitochondrial genes, and possesses an organelle believed to be a m ...
,
Apusomonadida and
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 ...
a. The term Obazoa is based on the OBA
acronym
An acronym is a word or name formed from the initial components of a longer name or phrase. Acronyms are usually formed from the initial letters of words, as in ''NATO'' (''North Atlantic Treaty Organization''), but sometimes use syllables, as ...
for Opisthokonta, Breviatea, and Apusomonadida.
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
animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...
s and
fungi
A fungus ( : fungi 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 a kingdom, separately from ...
emerged.
The relationships among opisthokonts, breviates and apusomonads are not conclusively resolved (as of 2018), 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 (see for example:
), probably reflecting their stemming from a very ancient common ancestor, and little
phylogenetic signal
Phylogenetic signal is an evolutionary and ecological term, that describes the tendency or the pattern of related biological species to resemble each other more than any other species that is randomly picked from the same phylogenetic tree.
Cha ...
remains in datasets consisting of one or a few genes.
References
{{Taxonbar, from=Q22087764
Amorphea unranked clades