Cruciplacolithus klausii

Classification: ntax_cenozoic -> Coccolithales -> Coccolithaceae -> Cruciplacolithus -> Cruciplacolithus klausii
Sister taxa: C. neohelis, C. kanungoi ⟩⟨ C. cruciformis, C. flavius, C. klausii, C. nishii, C. tarquinius ⟩⟨ C. asymmetricus, C. edwardsii, C. frequens ⟩⟨ C. intermedius, C. primus, C. subrotundus, C. tenuis ⟩⟨ C. filigranus, C. inseadus, C. latipons, C. sp.


Citation: Cruciplacolithus klausii Bown & Dunkley Jones, 2012
Rank: Species
Synonyms: Cruciplacolithus opacus Shamrock & Watkins 2012 [my interpretation JRY 2015, the descriptions and illustrations of C. opacus and C. klausii are virtually identical. NB  The publication date for C. klausii (JNR issue 32/2) is May 2012, the publication date for C. opacus (Stratigraphy issue 9/1) is October 2012 - both dates provided by the publishers. Hence C. klausii has priority - JRY Nov 2016. Thibault et al. (2018, p.218)) also consider C. opacus a synonym of C. klausii].
Taxonomic discussion: Distinguised from other Cruiplacolithus species by the indistinct tube cycle and low birefringence appearance in XPL.

Distinguishing features: Medium to large sized (~6-10µm), elliptical placolith coccoliths with a low birefringence rim and narrow central area almost filled by broad low birefringence axial cross bars. The brigher tube cycle may be indistinct.

Farinacci & Howe catalog pages: C. opacus * , C. klausii *

Size: Holotype length 7.0 microns.

Search data:
TagsLITHS: placolith, elliptical, CA: cross-axial, ca_disjunct, closed,
CSPH: equant, monomorphic, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent,
MetricsLith size: 6->10µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within NP25 zone (24.40-26.84Ma, top in Chattian stage). Data source: Bown & Dunkley Jones, 2012
First occurrence (base): within NP15 zone (42.87-46.29Ma, base in Lutetian stage). Data source: Shamrock & Watkins 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 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

Thibault, N., Minoletti, F. & Gardin, S. (2018). Offsets in the early Danian recovery phase in carbon isotopes: Evidence from the biometrics and phylogeny of the Cruciplacolithus lineage. Revue de Micropaléontologie. 61(2): 207-221. gs


Cruciplacolithus klausii compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 28-2-2021

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