Nannotax3 - ntax_mesozoic - Rhagodiscus sageri Nannotax3 - ntax_mesozoic - Rhagodiscus sageri

Rhagodiscus sageri


Classification: ntax_mesozoic -> Eiffellithales -> Rhagodiscaceae -> Rhagodiscus -> Rhagodiscus sageri
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. sicutclipeus ⟩⟨ R. eboracensis, R. hamptonii, R. reniformis, R. sp.

Distinguishing features:
Parent taxon (Rhagodiscus): Loxolith coccoliths with low rim and central-area filled by a granular plate which may be perforate and/or spine-bearing. In xpl the rim is unicyclic moderately bright, the central area is granular, lacking a clear extinction cross.
This taxon: Large, central area relatively broad and spanned by, raised, bridge-like structure.


Taxonomy:

Citation: Rhagodiscus sageri Bown, 2005
Rank: Species

Farinacci & Howe catalog pages: R. sageri *

Distinguishing features:
Parent taxon (Rhagodiscus): Loxolith coccoliths with low rim and central-area filled by a granular plate which may be perforate and/or spine-bearing. In xpl the rim is unicyclic moderately bright, the central area is granular, lacking a clear extinction cross.
This taxon: Large, central area relatively broad and spanned by, raised, bridge-like structure.


Morphology:

Similar in general morphology to Rhagodiscus asper but distinguished by the raised ridge/bridge of the central area plate.

Search data:
LITHS: murolith, elliptical, CA: plate, process, bar, CROSS-POLARS: rim-unicyclic, R-prominent,
Lith size: 8->10µm;
Data source notes: original description & illustrated specimens
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within Cenomanian Stage (93.9-100.5Ma, top in Cenomanian stage). Data source: Bown 2005
First occurrence (base): within NC4 zone (132.87-132.93Ma, base in Hauterivian stage). Data source: Bown 2005

Plot of occurrence data:

References:

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 O


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Rhagodiscus sageri compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 2-12-2023

Taxon Search:
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Short stables page link: https://mikrotax.org/Nannotax3/index.php?id=11031 Go to Archive.is to create a permanent copy of this page - citation notes



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