| Placidozoa | |
|---|---|
 | |
| Opalina ranarum, a species of placidozoan | |
Scientific classification  | |
| Domain: | Eukaryota |
| Clade: | Diaphoretickes |
| Clade: | SAR |
| Clade: | Stramenopiles |
| Phylum: | Bigyra |
| Subphylum: | Opalozoa |
| Infraphylum: | Placidozoa Cavalier-Smith 2013 [1] |
| Classes | |
Placidozoa is a recently defined non-photosynthetic lineage of Stramenopiles. [1] [2]
In 2016, Philippe Silar presented the following phylogeny for the Placidozoa: [3]
| Placidozoa | |
Infraphylum PlacidozoaCavalier-Smith 2013
Euglenozoa are a large group of flagellate Discoba. They include a variety of common free-living species, as well as a few important parasites, some of which infect humans. Euglenozoa are represented by four major groups, i.e., Kinetoplastea, Diplonemea, Euglenida, and Symbiontida. Euglenozoa are unicellular, mostly around 15–40 μm (0.00059–0.00157 in) in size, although some euglenids get up to 500 μm (0.020 in) long.
Pedinellales is a group of single-celled algae found in both marine environments and freshwater.
The metamonads are a large group of flagellate amitochondriate microscopic eukaryotes. Their composition is not entirely settled, but they include the retortamonads, diplomonads, and possibly the parabasalids and oxymonads as well. These four groups are all anaerobic, occurring mostly as symbiotes or parasites of animals, as is the case with Giardia lamblia which causes diarrhea in mammals.
The Archamoebae are a group of protists originally thought to have evolved before the acquisition of mitochondria by eukaryotes. They include genera that are internal parasites or commensals of animals. A few species are human pathogens, causing diseases such as amoebic dysentery. The other genera of archamoebae live in freshwater habitats and are unusual among amoebae in possessing flagella. Most have a single nucleus and flagellum, but the giant amoeba Pelomyxa has many of each.
Bicosoecida (ICZN) or Bicosoecales/Bicoecea (ICBN) is an order of Bikosea, a small group of unicellular flagellates, included among the stramenopiles. Informally known as bicosoecids, they are a small group of unicellular flagellates. The cells are free-living, with no chloroplasts, and in some genera are encased in a lorica.
The raphidophytes, formally known as Raphidophycidae or Raphidophyceae, are a small group of eukaryotic algae that includes both marine and freshwater species. All raphidophytes are unicellular, with large cells, but no cell walls. Raphidophytes possess a pair of flagella, organised such that both originate from the same invagination. One flagellum points forwards, and is covered in hair-like mastigonemes, while the other points backwards across the cell surface, lying within a ventral groove. Raphidophytes contain numerous ellipsoid chloroplasts, which contain chlorophylls a, c1 and c2. They also make use of accessory pigments including β-carotene and diadinoxanthin. Unlike other heterokontophytes, raphidophytes do not possess the photoreceptive organelle typical of this group.
Opalinata is a superclass of non-phagotrophic heterokonts that unites the classes Opalinea and Blastocystea, and is the sister group to Opalomonadea.
Phaeothamniophycidae is a subclass of heterokont algae. It contains two orders, Phaeothamniales and Pleurochloridellales, and consists of species separated from Chrysophyceae.
Opalozoa is a subphylum of heterotrophic protists of the phylum Bigyra, and is the sister group to Sagenista. Opalozoans are non-photosynthetic heterokonts that are ancestrally phagotrophic but many times have evolved to be osmotrophic saprotrophs in the gut of vertebrate animals.
Dictyochophyceae sensu lato is a photosynthetic lineage of heterokont algae.
Aphelida is a phylum of Fungi that appears to be the sister to true fungi.
Raphidomonadea is a class of Stramenopiles containing both photosynthetic and phagotrophic protists. The phagotrophic groups are known as Raphopoda, and comprise actinophryid heliozoa and the marine genus Commation. The photosynthetic groups are known as the raphidophyte algae. Their relationship was elucidated through phylogenetic analyses.
Bicosidia is a subclass of Bikosea, a small group of unicellular flagellates, included among the heterokonts.
Rictus is a genus of Bikosea, a small group of unicellular flagellates, included among the heterokonts. The only species in the genus is Rictus lutensis.
Solenicola setigera is a species of marine stramenopile, and the only species classified within the genus Solenicola.
Opalomonadea is a class of biciliate phagotrophic opalozoans with an anterior hairy cilium, often from anaerobic habitats. It is a monophyletic group previously known as clade MAST-12, sister to Opalinata. This group was discovered through marine environmental DNA samples; no species have yet been described or cultured.
Wobblata is a paraphyletic grouping of all placidozoans except Opalinata. It unites the classes Placididea, Nanomonadea and Opalomonadea.
Nanomonadea is a class of biciliate phagotrophic, non-photosynthetic free-living opalozoans, coontaining the sole order Uniciliatida. This monophyletic group previously known as clade MAST-3 is characterized by a single hairless posterior cilium and absence of an anterior cilium.
Gyrista is a phylum of heterokont protists containing three diverse groups: the mostly photosynthetic Ochrophyta, the parasitic Pseudofungi, and the recently described group of nanoflagellates known as Bigyromonada. Members of this phylum are characterized by the presence of a helix or a double helix/ring system in the ciliary transition region.
Raphopoda is a grouping of heterotrophic protists. It contains the heterotroph organisms within class Raphidomonadea, classified as two orders: Commatiida, comprised by the sole genus of flagellates Commation, and Actinophryida, an order of heliozoa, amoebae with stiff specialized pseudopodia called axopodia.