View source for Polycystine

{{Short description|Class of single-celled organisms}}
{{Automatic taxobox
| image = Radiolarian.png
| image_alt = Skeleton of a polycystine
| image_caption = Skeleton of a polycystine
| taxon = Polycystina
| authority = [[Christian Gottfried Ehrenberg|Ehrenberg]], 1838, ''[[emend.]]'' [[Ernst Haeckel|Haeckel]], 1887
| synonyms = 
| synonyms_ref = 
| subdivision_ranks = Orders
| subdivision_ref = <ref>WoRMS (2019). Polycystina. Accessed at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=235740 on 2019-01-08 </ref>
| subdivision = 
*[[Collodaria]] <small></small>
*[[Nassellaria]] <small></small>
*[[Spumellaria]] <small></small>
}}
{{one source|date=February 2022}}

The '''polycystines''' are a group of [[radiolarian]]s. They include the vast majority of the [[fossil]] radiolaria, as their skeletons are abundant in marine sediments, making them one of the most common groups of microfossils.  These skeletons are composed of [[opal]]ine silica.  In some it takes the form of relatively simple spicules, but in others it forms more elaborate lattices, such as concentric spheres with radial spines or sequences of conical chambers. Two of the orders belonging to this group are the radially-symmetrical [[Spumellaria]], dating back to the late [[Cambrian]] period, and the bilaterally-symmetrical Nasselaria, whose origin is placed within the lower [[Devonian]].<ref>[https://tel.archives-ouvertes.fr/tel-03137926/file/MENDEZ_SANDIN_Miguel_2019.pdf], Mendez Sandin. Diversity and Evolution of Nassellaria and Spumellaria (Radiolaria). Protistology. Sorbonne Université, 2019. English. Accessed at: https://tel.archives-ouvertes.fr/tel-03137926/file/MENDEZ_SANDIN_Miguel_2019.pdf on 2022-10-18</ref>

[[File:2023 PolycystineWHOLE.svg|thumb|left|upright=2|{{center|Representation of a whole Polycystine}}{{ordered list|
Spine (silica)|
Cytokalymma|
[[Pseudopodia|Axopodium]]|
[[Filopodia|Filopodium]], a cytoplasmic projection|
Alveoli, surface cavities or pits|
Reticulopodial network|
Cortical shell (skeleton)|
Central capsule|
[[Cell nucleus|Nucleus]]|
Axoplast|
Medullary shell (silica skeleton)|
[[Food vacuole|Digestive vacuole]]|
[[Phagosome|Phagocytic vacuoles]]|
Prey|
Algal [[symbiont]]}}]]

[[Image:Haeckel Spumellaria.jpg|thumb|left|An illustration of polycystines of the subclass [[Spumellaria]], from [[Ernst Haeckel]]'s 1904 ''[[Kunstformen der Natur]]'' (Artforms of Nature)]]



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== References ==
{{reflist}}

== External links ==
* {{Wikispecies-inline|Polycystinea}}
* {{Cite web | url=http://www.ucmp.berkeley.edu/protista/radiolaria/radsy.html | title=Systematics of the Radiolaria}}
* [http://www.radiolaria.org/ Radiolaria.org]
* {{Cite web | url=http://tolweb.org/Polycystina/121189|title=Polycystine radiolarians|archive-url=https://web.archive.org/web/20240509021211/http://tolweb.org/Polycystina/121189|archive-date=2024-05-09}}

{{Rhizaria}}
{{Taxonbar|from=Q3314313}}

[[Category:Taxa named by Christian Gottfried Ehrenberg]]
<!-- [[Category:Eukaryote classes]] moved to "Polycystinea" redirect -->
{{Radiolarian-stub}}