Monothalamea

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Monothalamea
Image of a deep sea
xenophyophore
Scientific classification Edit this classification
Domain: Eukaryota
Clade: Diaphoretickes
Clade: SAR
Phylum: Retaria
Subphylum: Foraminifera
Class: Monothalamea
emend. Pawlowski et al., 2013[2]
Orders and subtaxa incertae sedis[3]

"Monothalamea" is a grouping of foraminiferans, traditionally consisting of all foraminifera with single-chambered tests. Recent work has shown that the grouping is paraphyletic, and as such does not constitute a natural group; nonetheless, the name "monothalamea" continues to be used by foraminifera workers out of convenience.[4]

Classification

"Monothalamea" traditionally contains two groups, neither of which is currently considered to be monophyletic:

  • "Allogromiida" traditionally consists of all foraminifera which lack a mineralised test, instead having a test of tectin. Recent work has shown that this grouping is paraphyletic.
  • "Astrorhizida" traditionally consists of all foraminifera with single-chambered, agglutinated tests. Recent work has shown that this grouping is polyphyletic, as agglutinated tests have evolved from proteinaceous tests multiple times throughout foraminiferal evolution.[4]

Recent molecular evidence has revealed that the deep-sea xenophyophores are in fact agglutinated, single-chambered foraminifera.[5] Molecular evidence has also revealed that the freshwater protist Reticulomyxa is in fact a naked, testless foraminifera, and as such it has been included with "monothalameans" in scientific discussion.[4][6]

A 2013 molecular study using small subunit rDNA concluded that known "monothalameans" made up at least 22 distinct living clades from marine environments with an additional four clades from freshwater eDNA.[4]

References

  1. ^ Ernst Haeckel: Die Radiolarien (Rhizopoda Radiaria). Berlin, 1862
  2. . Retrieved 7 January 2019.
  3. ^ Hayward, B.W.; Le Coze, F.; Gross, O. (2019). World Foraminifera Database. Monothalamea. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=744106 on 2019-01-07
  4. ^
    ISSN 0377-8398
    .
  5. .
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Further reading

External links