Nannotax3 - ntax_mesozoic - Rhagodiscus amplus

Rhagodiscus amplus


Classification: ntax_mesozoic -> Eiffellithales -> Rhagodiscaceae -> Rhagodiscus -> Rhagodiscus amplus
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 (>8.0 µm) loxolith coccoliths with a wide central area (usually greater than twice as wide as the rim) that is spanned by a granular plate. A relatively large spine or spine base is typically present. The rim and plate usually show yellow interference colors in XPL.


Taxonomy:

Citation: Rhagodiscus amplus Bown, 2005
Rank: Species

Farinacci & Howe catalog pages: R. amplus *

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 (>8.0 µm) loxolith coccoliths with a wide central area (usually greater than twice as wide as the rim) that is spanned by a granular plate. A relatively large spine or spine base is typically present. The rim and plate usually show yellow interference colors in XPL.


Morphology:

Similar in general morphology to Rhagodiscus asper, but distinguished by its larger size.

Size:
Holotype length = 9.8µm


Ecology & Biogeography


Biology & life-cycles

Phylogenetic relations

Search data:
LITHS: murolith, elliptical, CA: plate, process, 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 NC8b subzone (110.73-112.65Ma, top in Albian stage). Data source: Bown 2005
First occurrence (base): within NC6a subzone (125.95-126.40Ma, base in Barremian 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

Gale, A. S. et al. (2011). The uppermost Middle and Upper Albian succession at the Col de Palluel, Hautes-Alpes, France: An integrated study (ammonites, inoceramid bivalves, planktonic foraminifera, nannofossils, geochemistry, stable oxygen and carbon isotopes, cyclostratigraphy). Cretaceous Research. 32: 59-130. gs

Kennedy, W. J. et al. (2000). Integrated stratigraphy across the Aptian-Albian boundary in the Marnes Bleues, at the Col de Pre _-Guittard, Arnayon (Drome), and at Tartonne (Alpes-de-Haute-Provence), France: a candidate Global Boundary Stratotype Section and Boundary Point for the base of the Albian Stage. Cretaceous Research. 21: 591-720. gs


nannotaxlogo400px

Rhagodiscus amplus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 3-12-2022

Taxon Search:
Advanced Search

Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=11015 Go to Archive.is to create a permanent copy of this page - citation notes



Comments (0)

No comments yet on this page. Please do add comments if you spot any problems, or have information to share

Add Comment

* Required information
1000
Captcha Image
Powered by Commentics