Polycystine

Polycystinea
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Polycystine skeleton
Scientific classification
(unranked):	SAR
(unranked):	Rhizaria
Phylum:	Retaria
Subphylum:	Radiozoa
Class:	Polycystinea
Orders
Spumellaria Nassellaria

The polycystines are a group of radiolarian protists. 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 opaline 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.

An illustration of polycystines of the subclass Spumellaria, from Ernst Haeckel's 1904 Kunstformen der Natur (Artforms of Nature)

References

• Systematics of the Radiolaria

External links

• Radiolaria.org
• Tree of Life: Polycystine Radiolarians