Taxonomy:
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]
Tags | LITHS: placolith, elliptical, CA: ca_disjunct, plate, pores, CSPH: equant, monomorphic, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent, |
Metrics | Lith size: 10->14µm; |
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. gsReferences:
![]() |
Clausicoccus norrisii compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 20-4-2021
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=307 Go to Archive.is to create a permanent copy of this page - citation notes |