Distinguishing features:
Parent taxon (C. pacificanus group): Medium-sized Eocene calcidiscid coccoliths with narrow or closed central-area.
This taxon: Medium to large (~7-10µm), broadly elliptical placolith coccoliths with broad bicyclic rim (in XPL) and vacant, narrow central area. The rim width is greater than the central area width (rim width/central area width: 1.6-1.9).
Farinacci & Howe catalog pages:
C. kamikurii *
| LITHS: placolith, circular, elliptical, CA: vacant, CSPH: equant, monomorphic, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent, |
| Lith size: 7->10µm; |
Geological Range:
Last occurrence (top): within NP24 zone (26.84-29.62Ma, top in Chattian stage). Data source: Bown & Dunkley Jones, 2012
First occurrence (base): within NP23 zone (29.62-32.02Ma, base in Rupelian stage). Data source: Bown & Dunkley Jones, 2012
Plot of occurrence data:
Bown, P. R. & Dunkley Jones, T. (2012). Calcareous nannofossils from the Paleogene equatorial Pacific (IODP Expedition 320 Sites U1331-1334). Journal of Nannoplankton Research. 32(2): 3-51. gs O De Kaenel, E. & Mojon, P. -O. (2023). Calcareous nannofossil biostratigraphy of the Eocene/Oligocene boundary (Zones NP19–21) in the parautochthonous Subalpine UMM of the Swiss Molasse Basin (Canton Fribourg, Western Switzerland). Journal of Nannoplankton Research. 41(2): 64-96. gs OReferences:

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Calcidiscus kamikurii compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 8-2-2026
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=178 Go to Archive.is to create a permanent copy of this page - citation notes |
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