Clausicoccus norrisii

Classification: ntax_cenozoic -> Coccolithales -> Coccolithaceae -> Clausicoccus -> Clausicoccus norrisii
Sister taxa: C. fenestratus, C. norrisii, C. subdistichus, C. vanheckiae, C. sp.


Citation: Clausicoccus norrisii Bown & Newsam 2017
Rank: Species
Taxonomic discussion: Shamrock & Watkins (2012) discussed the utility of separating large morphotypes of Clausicoccus and documented its occurrence through much of the Eocene. They applied the name Cruciplacolithus cribellum (Bramlette & Sullivan 1961) Romein 1979 to them. However, Bown & Newsam (2017), argue that the name C. cribellum is inappropriate since the holotype of Bramlette & Sullivan (1961) does not show the typical features of these large forms and hence they propsed the new name C. norrisii. 

Distinguishing features: Large Clausicoccus (>10µm) with wide shield and bright but indistinctly perforate central area plate.

Farinacci & Howe catalog pages: C. norrisii *

Morphology: Large, broadly elliptical coccolithacean coccolith with broad shields and moderately wide central area (similar to shield width) spanned by a plate that is indistinctly perforate and crossed by strong diagonal extinction lines. The bright inner cycle is relatively indistinct.
Differentiation: Distinguised from other Clausicoccus by larger size, relatively wider shield and bright but indistinctly perforate central area plate. [Bown & Newsam 2017]

Size: Holotype L = 12.7μm (Paratype L = 10.6μm). [Bown & Newsam 2017]

Search data:
TagsLITHS: placolith, elliptical, CA: ca_disjunct, plate, pores,
CSPH: equant, monomorphic, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent,
MetricsLith size: 10->14µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within NP17 zone (37.32-40.40Ma, top in Priabonian stage). Data source: Shamrock & Watkins 2012
First occurrence (base): within NP11 zone (53.70-54.17Ma, base in Ypresian stage). Data source: Shamrock & Watkins 2012

Plot of occurrence data:


Bown, P. R. & Newsam, C. (2017). Calcareous nannofossils from the Eocene North Atlantic Ocean (IODP Expedition 342 Sites U1403–1411). Journal of Nannoplankton Research. 37(1): 25-60. gs V O

Bramlette, M. N. & Sullivan, F. R. (1961). Coccolithophorids and related nannoplankton of the Early Tertiary in California. Micropaleontology. 7(2): 129-188. gs

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

Romein, A. J. T. (1979). Lineages in Early Paleogene calcareous nannoplankton. Utrecht Micropaleontological Bulletin. 22: 1-231. gs V O

Shamrock, J. L. & Watkins, D. K. (2012). Eocene calcareous nannofossil biostratigraphy and community structure from Exmouth Plateau, Eastern Indian Ocean (ODP Site 762). Stratigraphy. 9(1): 1-11. gs


Clausicoccus norrisii compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 20-4-2021

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

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