phaeodarea phaeodarea phaeodarea, or phaeodaria, is a group of amoeboid cercozoan organisms. 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 "phaeodaria" from ernst haeckel's kunstformen der natur, 1904 scientific classification domain: eukaryota clade: diaphoretickes clade: sar phylum: cercozoa class: thecofilosea subclass: phaeodareahaeckel 1879 orders eodarida phaeogymnocellida phaeocystida opaloconchida phaeocalpida phaeoconchida phaeodendrida phaeogromida phaeosphaerida synonyms phaeodaria haeckel 1879 tripylea hertwig 1879 the term "radiozoa" has been used to refer to radiolaria when phaeodarea is explicitly excluded. 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. taxonomy phylogeny through phylogenetic analyses it has been discovered that phaeodarea is a monophyletic clade, but the historical orders and families comprising it aren't. instead, the clade consists of 11 subclades defined by morphological and phylogenetic values that do not correspond with the traditional orders and families: clade a clade b clade c clade d clade e clade f clade g clade h phaeogromidaphaeogromidaphaeocalpidaphaeospheridaphaeodendridaphaeoconchidaphaeocystidaphaeocystidaphaeogymnocellida clade i clade j clade k despite this, the current taxonomy by cavalier-smith maintains the original classification of suborders divided between two new orders: eodarida, containing phaeodarea with no silica skeleton or with a skeleton made of simple radiating spicules. contains two suborders: phaeogymnocellina and phaeocystina. opaloconchida, containing phaeodarea with a highly perforated, shell-like opaline silica skeleton. contains the remaining five suborders: phaeosphaeria, phaeocalpia, phaeogromia, phaeoconchia and phaeodendria. modern classification the modern classification is the following, with the subclass containing a total of 2 orders, 7 suborders, 16 families and 39 genera. order eodarida cavalier-smith 2012 suborder phaeogymnocellina (=phaeogymnocellida) cachon & cachon 1985 family phaeosphaeridae cachon-enjumet 1961 – phaeopyla, phaeodactylis, phaeosphaera family phaeodinidae cachon-enjumet 1961 – phaeodina family atlanticellidae cachon-enjumet 1961 – gymnocelia, halocelia, lobocelia, miracelia, planktonetta suborder phaeocystina (=phaeocystida) haeckel 1887 family aulacanthidae haeckel 1887 – aulacantha family astracanthidae haeckel 1887 – astracantha, castanella, castanissa order opaloconchida cavalier-smith 2012 suborder phaeosphaeria (=phaeocystida) haeckel 1887 family aulosphaeridae haeckel 1887 – aulosphaera, aularia, aulotractus family cannosphaeridae haeckel 1887 – coelocantha family sagosphaeridae haeckel 1887 – sagenoarium, sagenoscena, sagoscena suborder phaeocalpia (=phaeocalpida) haeckel 1887 family castanellidae haecker 1906 – castanea family circoporidae haeckel 1887 – circoporus, circospathis, haeckeliana family tuscaroridae haeckel 1887 – tuscarora, tuscarilla, tuscaretta family porospathidae borgert 1900 – porospathis family polypyramidae reschetnjak 1966 – polypyramis suborder phaeogromia (=phaeogromida) haeckel 1887 family challengeridae murray 1886 – challengeria, challengeron family medusettiidae haeckel 1887 – euphysetta, gazelletta, medusetta family lirellidae loeblich & tappan 1961 – borgertella, lirella suborder phaeoconchia (=phaeoconchida) haeckel 1887 family concharidae haeckel 1887 – conchidium suborder phaeodendria (=phaeodendrida) haeckel 1887 family coelodendridae haeckel 1887 – coelodendrum, coelographis