radiolaria - rads_cenozoic - Circodiscus radiolaria - rads_cenozoic - Circodiscus


Classification: rads_cenozoic -> Litheliidae -> Larnacillidae -> Circodiscus
Sister taxa: Circodiscus, Histiastrum, Phorticium
Daughter taxa (time control age-window is: 0-800Ma)
Circodiscus circularis

neptune records: 32
Circodiscus ellipticus

neptune records: 116
Circodiscus microporus

neptune records:
Circodiscus sp.

neptune records:


Citation: Circodiscus Kozlova, in Petrusevskaya & Kozlova 1972
Rank: genus
Basionym: Circodiscus
Taxonomic discussion: Has been assigned to Spongodiscidae, here assigned to Larnacillidae following new classification being developed by Suzuki & co-workers

Catalog entries: Circodiscus

Original description: Slightly convex skeleton with round or oval outline. Consists of frontal, sagittal and equatorial girdles, their wings connected to form regular round or oval rings. First system is of the ""Trizonium-type"" (in sensu Haeckel), its dimension = 30-40µm, with fully developed girdles; in the rest of them, only the equatorial girdle is fully developed; sagittal and frontal girdles terminate at the point of the junction with the ring of the previous system; distance between ‘width of rings) is considerably larger than the diameter of the central chamber. Soines (four main and four secondary) pass inside of the skeleton. Rim is smooth.


Biogeography and Palaeobiology

Biostratigraphic distribution

Geological Range:
Last occurrence (top): Extant. Data source: Total of range of species in this database
First occurrence (base): at base of Aquitanian Stage (0% up, 23Ma, in Aquitanian stage). Data source: Total of range of species in this database

Plot of occurrence data:


Petrushevskaya, M. G. & Kozlova, G. E. (1972). Radiolaria: Leg 14, Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project. 14: 459-648. gs O


Circodiscus compiled by the radiolaria@mikrotax project team viewed: 26-3-2023

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AphiaID: 493591 Nomenclatural data on WoRMS
Short stables page link: Go to to create a permanent copy of this page - citation notes

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