Helicosphaera robinsoniae


Classification: Coccolithophores -> Zygodiscales -> Helicosphaeraceae -> Helicosphaera -> H. lophota group -> Helicosphaera robinsoniae
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 robinsoniae Bown & Dunkley Jones, 2012
Rank: Species
Notes & discussion: Similar to H. compacta and H. clarissima but with anterior spur and indistinct disjunct birefringent oblique bar. H. recta has a conjunct, transverse bar.

Distinguishing features: Large Helicosphaera with birefringent blanket, indistinct but disjunct, birefringent oblique bar, and anterior spur.

Farinacci & Howe catalog pages: Helicosphaera robinsoniae *


Size: Holotype length 11.8 microns

Search data:
TagsLITHS: placolith, asymmetric, RIM: wing, CA: bar-diagonal NE-SW, bar-diagonal, bar,
CSPH: ellipsoidal-----, elongated, monomorphic, varimorphic, V-UNITS: distal shield, V-prominent, R-UNITS: blanket, c-str, px-plate, R-prominent, DETAILS: ca_disjunct, rim-bicyclic, isogyres kinked, isogyres oblique, isogyres separated,
MetricsLith size: 10->15┬Ám;
Sources:
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within NP22 zone (32.02-32.92Ma, top in Rupelian stage). Data source: Bown & Dunkley Jones, 2012
First occurrence (base): within NP21 zone (32.92-34.44Ma, base in Priabonian stage). Data source: Bown & Dunkley Jones, 2012

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:

    Boesiger, T. M., de Kaenel, E., Bergen, J. A., Browning, E. & Blair, S. A. , . (2017). Oligocene to Pleistocene taxonomy and stratigraphy of the genus Helicosphaera and other placolith taxa in the circum North Atlantic Basin. Journal of Nannoplankton Research. 37(2-3): 145-175. gs

    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


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    Helicosphaera robinsoniae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 2-4-2020

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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=683 Go to Archive.is to create a permanent copy of this page - citation notes



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