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Monadofilosa
Monadofilosa is a grouping of Cercozoa. (It is sometimes considered one of three, the other two being Phytomyxa and Reticulofilosa.) These organisms are single-celled amoeboid protists. Classification Monadofilosa includes the testaceans, which are testate filose amoeboids, and the cercomonads. It is sometimes described as Testaceafilosia and Sarcomonadea. It has also been described as Sarcomonadea ('' Cercomonas, Heteromita, Bodomorpha, Proleptomonas, Allantion''), Thecofilosea (''Cryptodifflugia, Cryothecomonas''), Spongomonadea ('' Spongomonas, Rhipidodendron''), and Imbricatea ('' Thaumatomonas, Thaumatomastix, Allas, Gyromitus, Euglypha, Trinema, Paulinella''). * The testaceans live both in marine and freshwater habitats, and in mosses. Members include '' Lecythium'', '' Pseudodifflugia'', ''Euglypha'' (a euglyphid), and ''Paulinella chromatophora''. * Cercomonads are flagellates that glide on their posterior cilium and/or generate filopodia. Members of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryomonadida
Cryomonadida is a group of heterotrophic Rhizaria, that belong to the Cercozoa. Characteristics Members of the Cryomonadida are single-celled organisms that are surrounded by a shell comprising layers of organic material. They possess two unequally long flagella, and a single nucleus with a distinct nucleolus. They have a laterally located cytostome, from which pseudopodia arise. Systematics The order Cryomonadida was erected in 1993 for the genus ''Cryothecomonas''. In 2005, Sina Adl ''et al.'' did not include the order in their classification, but placed the genus ''incertae sedis'' among the Cercozoa. It became clear, however, that other genera, and taxa known only from environmental DNA, belonged in this group, and so in 2008 Jan Pawlowski placed the Cryomonadida as part of the core Cercozoa. Within the Cercozoa, the sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ebriid
The Ebridea is a group of phagotrophic flagellate eukaryotes present in marine coastal plankton communities worldwide. ''Ebria tripartita'' is one of two (possibly four) described extant species in the Ebridea. Members of this group are named for their idiosyncratic method of movement (''ebrius'', "drunk"). Ebriids are usually encountered in low abundance and have a peculiar combination of ultrastructural characters including a large nucleus with permanently condensed chromosomes and an internal skeleton composed of siliceous rods. The taxonomic history of the group has been tumultuous and has included a variety of affiliations, such as silicoflagellates, dinoflagellates, 'radiolarians' and 'neomonads'. However, molecular phylogenies place them within Cercozoa Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead defined by molecular phylogenies of rRNA and actin or polyubiquitin. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tectosia
The tectofilosids are a group of filose amoebae with shells. These are composed of organic materials and sometimes collected debris, in contrast to the euglyphids, which produce shells from siliceous scales. The shell usually has a single opening, but in '' Amphitrema'' and a few other genera it has two on opposite ends. The cell itself occupies most of the shell. They are most often found on marsh plants such as ''Sphagnum''. This group was previously classified as the Gromiida or Gromiina. However, molecular studies separate ''Gromia'' from the others, which must therefore be renamed. They are placed among the Cercozoa, and presumably developed from flagellates like ''Cryothecomonas'', which has a similar test. However, only a few have been studied in detail, so their relationships and monophyly are not yet certain. In a recent classification, the group Tectofilosida was not used: Chlamydophryidae, Psammonobiotidae, Pseudodifflugiidae and Volutellidae were dispersally plac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tectofilosida
The tectofilosids are a group of filose amoebae with shells. These are composed of organic materials and sometimes collected debris, in contrast to the euglyphids, which produce shells from siliceous scales. The shell usually has a single opening, but in '' Amphitrema'' and a few other genera it has two on opposite ends. The cell itself occupies most of the shell. They are most often found on marsh plants such as ''Sphagnum''. This group was previously classified as the Gromiida or Gromiina. However, molecular studies separate ''Gromia'' from the others, which must therefore be renamed. They are placed among the Cercozoa, and presumably developed from flagellates like ''Cryothecomonas'', which has a similar test. However, only a few have been studied in detail, so their relationships and monophyly are not yet certain. In a recent classification, the group Tectofilosida was not used: Chlamydophryidae, Psammonobiotidae, Pseudodifflugiidae and Volutellidae were dispersally plac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemimastigida
Spironemidae is a family of heterotrophic flagellates, in the group Hemimastigophora. They vary in size and shape from the ellipsoid ''Hemimastix amphikineta'' (14 × 7 μm) to the vermiform ''Spironema terricola'' (43 × 3 μm), and are united by the possession of two rows of cilia, called kineties. Phylogenomic analysis shows that Hemimastigophora are a distinct and ancient lineage of eukaryotic organisms, forming a possible sister clade to the supergroup Diaphoretickes. Taxonomy * Order Hemimastigida Foissner, Blatterer & Foissner 1988 [Hemimastigophora Foissner, Blatterer & Foissner 1988 sensu Cavalier-Smith 1993; Hemimastigea Foissner, Blatterer & Foissner 1988; Hemimastigidea] ** Family Spironematellidae *** Genus ''Hemimastix'' Foissner, Blatterer & Foissner, 1988 **** Species '' H. amphikineta'' Foissner, Blatterer & Foissner, 1988 **** Species '' H. kukwesjijk'' Eglit & Simpson, 2018 *** Genus ''Stereonema'' Foissner& Foissner, 1993 non ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filosa
Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead defined by molecular phylogenies of rRNA and actin or polyubiquitin. They were the first major eukaryotic group to be recognized mainly through molecular phylogenies. They are the natural predators of many species of microbacteria and Archea. They are closely related to the phylum Retaria, comprising amoeboids that usually have complex shells, and together form a supergroup called Rhizaria. Characteristics The group includes most amoeboids and flagellates that feed by means of filose pseudopods. These may be restricted to part of the cell surface, but there is never a true cytostome or mouth as found in many other protozoa. They show a variety of forms and have proven difficult to define in terms of structural characteristics, although their unity is strongly supported by phylogenetic studies. Diversity Some cercozoans are grouped by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cercozoa
Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead defined by molecular phylogenies of rRNA and actin or polyubiquitin. They were the first major eukaryotic group to be recognized mainly through molecular phylogenies. They are the natural predators of many species of microbacteria and Archea. They are closely related to the phylum Retaria, comprising amoeboids that usually have complex shells, and together form a supergroup called Rhizaria. Characteristics The group includes most amoeboids and flagellates that feed by means of filose pseudopods. These may be restricted to part of the cell surface, but there is never a true cytostome or mouth as found in many other protozoa. They show a variety of forms and have proven difficult to define in terms of structural characteristics, although their unity is strongly supported by phylogenetic studies. Diversity Some cercozoans are grouped ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizaria
The Rhizaria are an ill-defined but species-rich supergroup of mostly unicellular eukaryotes. Except for the Chlorarachniophytes and three species in the genus Paulinella in the phylum Cercozoa, they are all non-photosynthethic, but many foraminifera and radiolaria have a symbiotic relationship with unicellular algae. A multicellular form, ''Guttulinopsis vulgaris'', a cellular slime mold, has also been described. This group was used by Cavalier-Smith in 2002, although the term "Rhizaria" had been long used for clades within the currently recognized taxon. 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. In the absence of an apomorphy, the group is ill-defined, and its composition has been very fluid. Some Rhizaria possess mineral exoskeleton (thecae or loricas), which is in differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tom Cavalier-Smith
Thomas (Tom) Cavalier-Smith, FRS, FRSC, NERC Professorial Fellow (21 October 1942 – 19 March 2021), was a professor of evolutionary biology in the Department of Zoology, at the University of Oxford. His research has led to discovery of a number of unicellular organisms (protists) and advocated for a variety of major taxonomic groups, such as the Chromista, Chromalveolata, Opisthokonta, Rhizaria, and Excavata. He was known for his systems of classification of all organisms. Life and career Cavalier-Smith was born on 21 October 1942 in London. His parents were Mary Maude (née Bratt) and Alan Hailes Spencer Cavalier Smith. He was educated at Norwich School, Gonville and Caius College, Cambridge (MA) and King's College London (PhD). He was under the supervision of Sir John Randall for his PhD thesis between 1964 and 1967; his thesis was entitled "''Organelle Development in'' Chlamydomonas reinhardii". From 1967 to 1969, Cavalier-Smith was a guest investigat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SAR Supergroup
The SAR supergroup, also just SAR or Harosa, is a clade that includes stramenopiles (heterokonts), alveolates, and Rhizaria. The name is an acronym derived from the first letters of each of these clades; it has been alternatively spelled "RAS". The term "Harosa" (at the subkingdom level) has also been used. The SAR supergroup is a node-based taxon. Note that as a formal taxon, "Sar" has only its first letter capitalized, while the earlier abbreviation, SAR, retains all uppercase letters. Both names refer to the same group of organisms, unless further taxonomic revisions deem otherwise. Members of the SAR supergroup were once included under the separate supergroups Chromalveolata (Chromista and Alveolata) and Rhizaria, until phylogenetic studies confirmed that stramenopiles and alveolates diverged with Rhizaria. This apparently excluded haptophytes and cryptomonads, leading Okamoto ''et al.'' (2009) to propose the clade Hacrobia to accommodate them. Phylogeny Based on a compi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
