Euglenozoa

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Euglenozoa
Temporal range: Stenian (over 1000 MYA) - present [1]
Two Euglena
Scientific classification Edit this classification
Domain: Eukaryota
Clade:
Discoba
Superphylum: Discicristata
Phylum: Euglenozoa
Cavalier-Smith, 1981[2]
Classes
  • Diplonemea
  • Euglenida
  • Kinetoplastea
  • Symbiontida (Postgaardia
    )

Euglenozoa are a large group of

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.[3]

Structure

Most euglenozoa have two flagella, which are inserted parallel to one another in an apical or subapical pocket. In some these are associated with a cytostome or mouth, used to ingest bacteria or other small organisms. This is supported by one of three sets of microtubules that arise from the flagellar bases; the other two support the dorsal and ventral surfaces of the cell.[4]

Some other euglenozoa feed through absorption, and many euglenids possess

endosymbiosis by a basal euglenozoan. Reproduction occurs exclusively through cell division. During mitosis, the nuclear membrane remains intact, and the spindle microtubules form inside of it.[4]

The group is characterized by the ultrastructure of the flagella. In addition to the normal supporting microtubules or

diplonemids and Postgaardi.[6]

Classification

Historically, euglenozoans have been treated as either plants or animals, depending on whether they belong to largely photosynthetic groups or not. Hence they have names based on either the International Code of Nomenclature for algae, fungi, and plants (ICNafp) or the International Code of Zoological Nomenclature (ICZN). For example, one family has the name Euglenaceae under the ICNafp and the name Euglenidae under the ICZN. As another example, the genus name Dinema is acceptable under the ICZN, but illegitimate under the ICNafp, as it is a later homonym of an orchid genus, so that the synonym Dinematomonas must be used instead.[7]

The Euglenozoa are generally accepted as monophyletic. They are related to

cristae, which only occurs in a few other groups.[8]
Both probably belong to a larger group of eukaryotes called the Excavata.[9] This grouping, though, has been challenged.[10]

Phylogeny

The phylogeny based on the work of Cavalier-Smith (2016):[11]

A consensus phylogeny following the review by Kostygov et al. (2021):[7]

Taxonomy

Cavalier-Smith (2016/2017)

The following classification of Euglenozoa is as described by Cavalier-Smith in 2016,[11] modified to include the new subphylum Plicomonada according to Cavalier-Smith et al (2017).[12]

Phylum Euglenozoa Cavalier-Smith 1981 emend. Simpson 1997 [Euglenobionta]

  • Subphylum Glycomonada Cavalier-Smith 2016
    • Class
      Diplonemea
       Cavalier-Smith 1993 emend. Simpson 1997 [Diplosonematea; Diplonemia Cavalier-Smith 1993]
      • Order
        Diplonemida
        Cavalier-Smith 1993 [Hemistasiida]
        • Family Hemistasiidae Cavalier-Smith 2016 [Entomosigmaceae]
        • Family Diplonemidae Cavalier-Smith 1993 [Rhynchopodaceae Skuja 1948 ex Cavalier-Smith 1993]
    • Class
      Kinetoplastea
       Honigberg 1963 emend. Margulis 1974 [Kinetoplastida Honigberg 1963; Kinetoplasta Honigberg 1963 stat. nov.]
  • Subphylum Plicomonada Cavalier-Smith 2017
    • Infraphylum Postgaardia Cavalier-Smith 2016 stat. nov. Cavalier-Smith 2017
      • Class
        Postgaardea
         Cavalier-Smith 1998 s.s. [Symbiontida Yubuki et al., 2009]
        • Order Bihospitida Cavalier-Smith 2016
        • Order
          Postgaardida
          Cavalier-Smith 2003
          • Family
            Calkinsiidae
            Cavalier-Smith 2016
          • Family
            Postgaardidae
            Cavalier-Smith 2016
    • Infraphylum
      Euglenoida
       Bütschli 1884 emend. Senn 1900 stat. nov. Cavalier-Smith, 2017 [Euglenophyta; Euglenida Buetschli 1884; Euglenoidina Buetschli 1884]
      • Parvphylum Entosiphona Cavalier-Smith 2016 stat. nov. Cavalier-Smith 2017
      • Parvphylum Dipilida Cavalier-Smith 2016 stat. nov. Cavalier-Smith 2017
        • Superclass Rigimonada* Cavalier-Smith 2016
        • Superclass Spirocuta Cavalier-Smith 2016
          • Class Peranemea Cavalier-Smith 1993 emend. Cavalier-Smith 2016
            • Subclass Acroglissia Cavalier-Smith 2016
            • Subclass Peranemia Cavalier-Smith 2016
              • Order Peranemida Bütschli 1884 stat. nov. Cavalier-Smith 1993
                • Family Peranematidae [Peranemataceae Dujardin 1841; Pseudoperanemataceae Christen 1962]
            • Subclass Anisonemia Cavalier-Smith 2016
              • Order
                Anisonemida
                Cavalier-Smith 2016 [Heteronematales Leedale 1967]
                • Family Anisonemidae Saville Kent, 1880 em. Cavalier-Smith 2016 [Heteronemidae Calkins 1926; Zygoselmidaceae Kent 188]
              • Order Natomonadida Cavalier-Smith 2016
                • Suborder Metanemina Cavalier-Smith 2016
                • Suborder Rhabdomonadina Leedale 1967 emend. Cavalier-Smith 1993 [Astasida Ehrenberg 1831; Rhabdomonadia Cavalier-Smith 1993; Rhabdomonadophyceae; Rhabdomonadales]
                  • Family Distigmidae Hollande, 1942
                  • Family Astasiidae Saville Kent, 1884 [Astasiaceae Ehrenberg orth. mut. Senn 1900; Rhabdomonadaceae Fott 1971; Menoidiaceae Buetschli 188; Menoidiidae Hollande, 1942]
          • Class
            Euglenophyceae
             Schoenichen 1925 emend. Marin & Melkonian 2003 [Euglenea Bütschli 1884 emend. Busse & Preisfeld 2002; Euglenoidea Bütschli 1884; Euglenida Bütschli 1884] (Photosynthetic clade)
            • Subclass Rapazia Cavalier-Smith 2016
            • Subclass Euglenophycidae Busse and Preisfeld, 2003
              • Order Eutreptiida [Eutreptiales Leedale 1967 emend. Marin & Melkonian 2003; Eutreptiina Leedale 1967]
              • Order
                Euglenida
                Ritter von Stein, 1878 stat. n. Calkins, 1926 [Euglenales Engler 1898 emend. Marin & Melkonian 2003; Euglenina Buetschli 1884; Euglenomorphales Leedale 1967; Colaciales Smith 1938]
                • Family Euglenamorphidae Hollande, 1952 stat. n. Cavalier-Smith 2016 [Euglenomorphaceae; Hegneriaceae Brumpt & Lavier 1924]
                • Family Phacidae [Phacaceae Kim et al. 2010]
                • Family
                  Euglenidae
                  Bütschli 1884 [Euglenaceae Dujardin 1841 emend. Kim et al. 2010; Colaciaceae Smith 1933] (Mucilaginous clade)

Kostygov et al. (2021)

Phylum Euglenozoa Cavalier-Smith 1981 emend. Simpson 1997[7]

References

  1. PMID 28429314
    .
  2. PMID 7337818
    .
  3. ^ "Euglenozoa". Encyclopedia of Life. National Museum of Natural History - Smithsonian Institution. Retrieved 16 January 2020.
  4. ^
    S2CID 4367158
    .
  5. PMID 21622904
    .
  6. doi:10.1016/s0003-9365(97)80012-7
    .
  7. ^
    PMID 33715388
    .
  8. PMID 11062127
    .
  9. PMID 14657103
    .
  10. PMID 20031978
    .
  11. ^
    PMID 27889663
    .
  12. PMID 29073503
    .

External links