Helicosphaera compacta


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

Distinguishing features: Elliptical Helicosphaera with well defined birefringent blanket in XPL and narrow central area spanned by a conjunct bar.


Taxonomy:

Citation: Helicosphaera compacta Bramlette & Wilcoxon, 1967
Rank: Species
Variants: Helicosphaera moorkensii Steurbaut, 1983 - closed central area (no pores) - NP23

Farinacci & Howe catalog pages: Helicosphaera compacta * Helicosphaera moorkensii *

Distinguishing features: Elliptical Helicosphaera with well defined birefringent blanket in XPL and narrow central area spanned by a conjunct bar.

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

Geological Range:
Last occurrence (top): within NP24 zone (26.84-29.62Ma, top in Chattian stage). Data source: de Kaenel & Villa, 1996; Boesiger et al 2017
First occurrence (base): within NP16 zone (40.40-42.87Ma, base in Lutetian stage). Data source: [PRB rough estimate]

Plot of occurrence data:

  • Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
  • Taxon plotted: Helicosphaera compacta, synonyms included - Helicopontosphaera compacta; Helicosphaera compacta; space-time plot :: Samples map :: Parent: H. lophota group

    References:

    Bramlette, M.N. & Wilcoxon, J.A., (1967). Middle Tertiary calcareous nannoplankton of the Cipero section, Trinidad, W.I. Tulane Studies in Geology and Paleontology, 5: 93-131.

    Steurbaut, E., (1983). The stratigraphic position of the Lower Oligocene Yrieu Sainds (SW France, based on calcareous nannofossils and a new Helicosphaera species. Eclogae Geologicae Helvetiae, 76(2): 327-331.

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    Helicosphaera compacta compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 17-12-2018

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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=657Go to Archive.is to create a permanent copy of this page - citation notes
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    Comments (1)

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    Simon Cole (UK)
    Hi Jeremy
    I've always put the LO of H. compacta intra-NP24, approximated to the top of the Early Oligocene (28.09 according to GTS2012). I believe this is where de Kaenel & Villa, 1996 observed it too in most of their sections from the Iberia Abyssal Plain. Would you consider amending the absolute age here to reflect this?
    Cheers,
    Simon
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    Ines Galovic (Croatia)
    Maybe in IAP LO of the species marks the end of E. Oligocene, but in other Oceans (ODP, IODP and in other articles) its rare appearance certainly is in the Late Oligocene i.e. NP25, like in Adriatic (Mediterranean area)-mine observation.
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