Helicosphaera clarissima


Classification: Coccolithophores -> Zygodiscales -> Helicosphaeraceae -> Helicosphaera -> H. lophota group -> Helicosphaera clarissima
Sister taxa: H. clarissima, H. compacta, H. disrupta, H. reticulata, H. robinsoniae, H. bramlettei, H. lophota, H. papillata, H. prolixa, H. seminulum, H. wilcoxonii,

Taxonomy:

Citation: Helicosphaera clarissima Bown, 2005
Rank: Species
Notes & discussion: Helicosphaera neolophota Bukry 1984 has similar shape but blanket extends over the flange

Distinguishing features: Large elliptical to almond-shaped Helicosphaera with well defined birefringent blanket in XPL and a central area spanned by a broad, oblique, disjunct birefringent bar.

Farinacci & Howe catalog pages: Helicosphaera clarissima *

Search data:
TagsLITHS: placolith, asymmetric, RIM: wing, CA: bar-diagonal NE-SW, bar-diagonal,
CSPH: ellipsoidal, varimorphic, V-UNITS: distal shield, R-UNITS: blanket, c-str, px-plate, DETAILS: ca_disjunct, rim-bicyclic, isogyres kinked, isogyres oblique, isogyres separated,
MetricsLith size: 8->12µm;
Sources:
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within NP19-20 zone (34.44-36.97Ma, top in Priabonian stage). Data source: [PRB rough estimate]
First occurrence (base): within NP16 zone (40.40-42.87Ma, base in Lutetian stage). Data source: [PRB rough estimate]

Plot of occurrence data:

  • (NB There is no histogram as there are no occurrence records for the taxon in the Neptune database) Parent: H. lophota group

    References:

    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

    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

    Bown, P. R. (2005d). Palaeogene calcareous nannofossils from the Kilwa and Lindi areas of coastal Tanzania (Tanzania Drilling Project 2003-4). Journal of Nannoplankton Research. 27(1): 21-95. gs

    Bukry, D. (1984). Correlation of the middle Eocene Kellogg Shale of northern California. Micropaleontology. 30(2): 138-170. gs


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    Helicosphaera clarissima compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 21-9-2019

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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=656 Go to Archive.is to create a permanent copy of this page - citation notes



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