Discosea

{{Short description|Class of amoebae}}

{{Automatic taxobox

| image = Parasite140120-fig3 Acanthamoeba keratitis.png

| image_caption = Acanthamoeba sp.

| taxon = Discosea

| authority = Cavalier-Smith et al. 2004{{Cite journal|last=Cavalier-Smith|first=Thomas|last2=Chao|first2=Ema E. -Y.|last3=Oates|first3=Brian|date=2004-05-18|title=Molecular phylogeny of Amoebozoa and the evolutionary significance of the unikont Phalansterium|journal=European Journal of Protistology|volume=40|issue=1|pages=21–48|doi=10.1016/j.ejop.2003.10.001}}

| subdivision_ranks = Subclasses and orders

| subdivision_ref = {{cite journal | vauthors = Kang S, Tice AK, Spiegel FW, Silberman JD, Pánek T, Cepicka I, Kostka M, Kosakyan A, Alcântara DM, Roger AJ, Shadwick LL, Smirnov A, Kudryavtsev A, Lahr DJ, Brown MW | display-authors = 6 | title = Between a Pod and a Hard Test: The Deep Evolution of Amoebae | journal = Molecular Biology and Evolution | volume = 34 | issue = 9 | pages = 2258–2270 | date = September 2017 | pmid = 28505375 | pmc = 5850466 | doi = 10.1093/molbev/msx162 }}

| subdivision =

• Order ?Hyalodiscida
• Order ?Stereomyxida
• Order ?Stygamoebida
• Subclass Centramoebia
• Order Centramoebida
• Order Himatismenida
• Order Pellitida
• Subclass Flabellinia
• Order Dactylopodida
• Order Dermamoebida
• Order Thecamoebida
• Order Vannellida

}}

Discosea is a class of Amoebozoa, consisting of naked amoebae with a flattened, discoid body shape. Members of the group do not produce tubular or subcylindrical pseudopodia, like amoebae of the class Tubulinea. When a discosean is in motion, a transparent layer called hyaloplasm forms at the leading edge of the cell (see lamellipodium). In some discoseans, short "subpseudopodia" may be extended from this hyaloplasm, but the granular contents of the cell do not flow into these, as in true pseudopodia. Discosean amoebae lack hard shells, but some, like Cochliopodium and Korotnevella secrete intricate organic scales which may cover the upper (dorsal) surface of the cell. No species have flagella or flagellated stages of life.{{Cite journal|last=Smirnov|first=Alexey V.|last2=Chao|first2=Ema|last3=Nassonova|first3=Elena S.|last4=Cavalier-Smith|first4=Thomas|date=2011-10-01|title=A revised classification of naked lobose amoebae (Amoebozoa: lobosa)|journal=Protist|volume=162|issue=4|pages=545–570|doi=10.1016/j.protis.2011.04.004|issn=1618-0941|pmid=21798804}}{{Cite journal|last=Adl|first=Sina M.|last2=Simpson|first2=Alastair G. B.|last3=Lane|first3=Christopher E.|last4=Lukeš|first4=Julius|last5=Bass|first5=David|last6=Bowser|first6=Samuel S.|last7=Brown|first7=Matthew W.|last8=Burki|first8=Fabien|last9=Dunthorn|first9=Micah|date=2012-09-01|title=The revised classification of eukaryotes|journal=The Journal of Eukaryotic Microbiology|volume=59|issue=5|pages=429–493|doi=10.1111/j.1550-7408.2012.00644.x|issn=1550-7408|pmc=3483872|pmid=23020233}}

The composition of Discosea is similar to that of the class Flabellinea, proposed by Alexey Smirnov and his collaborators in 2005.{{Cite journal|last=Smirnov|first=Alexey|last2=Nassonova|first2=Elena|last3=Berney|first3=Cédric|last4=Fahrni|first4=José|last5=Bolivar|first5=Ignacio|last6=Pawlowski|first6=Jan|date=2005-08-01|title=Molecular phylogeny and classification of the lobose amoebae|journal=Protist|volume=156|issue=2|pages=129–142|doi=10.1016/j.protis.2005.06.002|issn=1434-4610|pmid=16171181}} However, Discosea is a more comprehensive taxon, including several groups not included in Flabellinea.{{Cite web|url=http://coo.fieldofscience.com/2009/09/discosea-keeping-low-profile.html|title=Catalogue of Organisms: Discosea: Keeping a Low Profile|website=coo.fieldofscience.com|access-date=2016-05-03}} In 2011, Smirnov et al. accepted Discosea as a class, and reduced Flabellinea to the rank of a subclass with the name Flabellinia.

File:Parasite140120-fig3 Acanthamoeba keratitis Figure 3B.png|Acanthamoeba sp.

File:Thecamoeba striata001.JPG|Thecamoeba sp.

File:Строение амебы Mayorella sp.jpg|Mayorella (Amoebozoa, Discosea)