Phaeodarea

Taxobox
name = Phaeodarea


image_caption = "Phaeodaria" from Ernst Haeckel's "Kunstformen der Natur", 1904
domain = Eukaryota
unranked_phylum = Rhizaria
phylum = Cercozoa
classis = Phaeodarea
classis_authority = Haeckel, 1879

The Phaeodarea are a group of amoeboid protists. They are traditionally considered radiolarians, but in molecular trees do not appear to be close relatives of the other groups, and are instead placed among the Cercozoa. They are distinguished by the structure of their central capsule and by the presence of a phaeodium, an aggregate of waste particles within the cell.

Phaeodarea produce hollow skeletons composed of amorphous silica and organic material, which rarely fossilize. The endoplasm is divided by a cape with three openings, of which one gives rise to feeding pseudopods, and the others let through bundles of microtubules that support the axopods. Unlike true radiolarians, there are no cross-bridges between them. They also lack symbiotic algae, generally living below the photic zone, and do not produce any strontium sulphate.

References

* cite journal
first = Sergey I.
last = Nikolaev
coauthors = Cédric Berney, José F. Fahrni, Ignacio Bolivar, Stephane Polet, Alexander P. Mylnikov, Vladimir V. Aleshin, Nikolai B. Petrov, and Jan Pawlowski
title = The twilight of the Heliozoa and rise of the Rhizaria, an emerging supergroup of amoeboid eukaryotes
journal = Proceedings of the National Academy of Sciences
year = 2004 | volume = 101 | pages = 8066–8071 | issue = 21
issn = 0027-8424
url = http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=419558&rendertype=abstract
accessdate = 2007-06-08
doi = 10.1073/pnas.0308602101
pmid = 15148395