Classification: Coccolithophores -> Coccolithales -> Coccolithaceae -> Clausicoccus
Sister taxa: Coccolithus, Bramletteius, Campylosphaera, Chiasmolithus, Coronocyclus, Cruciplacolithus, Ericsonia, Solidopons, Birkelundia, Clausicoccus, Craticullithus, Hughesius, Kilwalithus,

Daughter taxa: (blue => in age window 0-800Ma)
Typical medium sized Clausicoccus species.
Large Clausicoccus (>10µm) with wide shield and bright but indistinctly perforate central area plate.
Small Clausicoccus with narrow central area typically equal to the rim width.
Large Clausicoccus with wide central area typically twice as broad or greater than rim width.
Specimens which cannot be assigned to established species


Citation: Clausicoccus Prins, 1979
Rank: Genus
Type species: Clausicoccus fenestratus (Deflandre & Fert, 1954) Prins, 1979. [Discolithus]
Notes & discussion: This is a common Late Palaeogene genus, many species of which have been described. These were asigned to various genera prior to description of Clausicoccus by Prins (1979). Only the single species C. fenestratus continues into the Miocene but this appears to give rise to Hughesius tasmaniae

Distinguishing features: Rim structure like Coccolithus; perforate plate covers the central area on the distal side

Farinacci & Howe catalog pages: Clausicoccus * , Clausibella *

Morphology remarks: Coccolith rim structure similar to that of Coccolithus, but with a perforate plate covering the central area on the distal side. Centro-distal cycle (bright in XPL) may be narrow or reduced.
The plate typically shows significant birefringence but also appears dark in phase contrast so it may, like the inner tube of Coccolithus, be formed of two layers the upper of R-units and the lower of V-units  

Search data:
TagsLITHS: placolith, elliptical, RIM: psh-bicyclic, CA: plate, pores,
CSPH: spherical, monomorphic, V-UNITS: distal shield, px-tube, R-UNITS: c-str, ds-tube, prox shield, DETAILS: ca_disjunct, rim-bicyclic, isogyres oblique,
MetricsLith size: 4.5->14µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): in lower part of Burdigalian Stage (32% up, 19Ma, in Burdigalian stage). Data source: Total of range of species in this database
First occurrence (base): in lower part of Ypresian Stage (22% up, 54.2Ma, in Ypresian stage). Data source: Total of range of species in this database

Plot of occurrence data:


Prins, B. (1979). Notes on nannology 1. Clausicoccus, a new genus of fossil Coccolithophorids. INA Newsletter. 1: N2-N4. gs


Clausicoccus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 22-10-2019

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Short stable page link: Go to to create a permanent copy of this page - citation notes

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