Rhagodiscus robustus


Classification: Mesozoic -> Eiffellithales -> Rhagodiscaceae -> Rhagodiscus -> Rhagodiscus robustus
Sister taxa: R. achlyostaurion, R. amplus, R. angustus, R. asper, R. cepekii, R. dekaenelii, R. infinitus, R. pseudoangustus, R. splendens, R. adinfinitus, R. gallagheri, R. indistinctus, R. pancostii, R. plebeius, R. robustus, R. sageri, R. eboracensis, R. hamptonii, R. reniformis, R. sp.,

Distinguishing features: Large (>8.0 µm) loxolith coccoliths with a broad rim (usually as broad or broader than the central area) and a central area spanned by a granular plate; a relatively large spine or spine base is usually present. The broad and blocky rim shows yellow interference colors under XPL.


Taxonomy:

Citation: Rhagodiscus robustus Bown, 2005
Rank: Species

Farinacci & Howe catalog pages: Rhagodiscus robustus *

Distinguishing features: Large (>8.0 µm) loxolith coccoliths with a broad rim (usually as broad or broader than the central area) and a central area spanned by a granular plate; a relatively large spine or spine base is usually present. The broad and blocky rim shows yellow interference colors under XPL.


Morphology remarks: Distinguished from other rhagodiscids by its large size and relatively closed central area, with some specimens resembling the Jurassic coccolith species Crepidolithus crassus. The Albian ‘Crepidolithus burwellensis Black, 1972 (holotype scanning electron micrograph [SEM] only) displays a Crepidolithus-like rim but is small (~4.0 µm) and has an open central area crossed by a transverse bar.

Size: Holotype length = 8.7µm

Search data:
TagsLITHS: murolith, elliptical, CA: process, R-UNITS: R-prominent, DETAILS: rim-unicyclic,
MetricsLith size: 8->12µm;
Sources: original description & illustrated specimens
The morphological data given here can be used on the advanced search page. See also these notes

See also: Zeugrhabdotus burwellensis - small species with some similarities;

Geological Range:
Last occurrence (top): within NC10a subzone (100.45-103.13Ma, top in Cenomanian stage). Data source: Bown 2005
First occurrence (base): within NC5 zone (126.40-132.87Ma, base in Hauterivian stage). Data source: Bown 2005

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
  • Note to users in China - the diagram may not plot unless you use a VPN since I use google services on the website. If this is a problem please contact me 谢谢.
  • Taxon plotted: Rhagodiscus robustus, synonyms included - Rhagodiscus robustus;
  • space-time plot :: Samples map :: Parent: Rhagodiscus

    References:

    Black, M. (1972a). British Lower Cretaceous Coccoliths. I-Gault Clay (Part 1). Palaeontographical Society Monograph. 126: 1-48. gs :: ::

    Bown, P. R. (2005c). Early to Mid-Cretaceous Calcareous Nannoplankton from the Northwest Pacific Ocean, Leg 198, Shatsky Rise. Proceedings of the Ocean Drilling Program, Scientific Results. 198: 1-82. gs :: view :: open

    Jeremiah, J. (1996). A proposed Albian to Lower Cenomanian nannofossil biozonation for England and the North Sea Basin. Journal of Micropalaeontology. 15(97-129): -. gs :: view :: open


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    Rhagodiscus robustus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 6-6-2020

    Taxon Search:
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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=11030 Go to Archive.is to create a permanent copy of this page - citation notes



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