Rhagodiscus adinfinitus

Classification: Mesozoic -> Eiffellithales -> Rhagodiscaceae -> Rhagodiscus -> Rhagodiscus adinfinitus
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: Medium-sized unicyclic loxolith coccoliths with a wide central area spanned by a butterfly-shaped bar with raised, birefringent edges.


Citation: Rhagodiscus adinfinitus Bown, 2005
Rank: Species

Farinacci & Howe catalog pages: Rhagodiscus adinfinitus *

Distinguishing features: Medium-sized unicyclic loxolith coccoliths with a wide central area spanned by a butterfly-shaped bar with raised, birefringent edges.

Morphology remarks: Similar to Rhagodiscus infinitus, with a central granular plate pierced by two large holes. However, R. infinitus has a plate that extends completely around the central area with distinct circular pores surrounded by raised, birefringent edges; whereas R. adinfinitus has only a broad, flaring bar (butterfly shaped) with raised edges that terminate against the inner edge of the rim. Older specimens are slightly smaller and have less flaring bars. The raised edges of the bar make an angle of ~20°-35° with the transverse axis increasing to 40°-50° in younger specimens. This may represent a shift in morphology toward the R. infinitus morphology.

Size: Length = 7.2µm

Search data:
TagsLITHS: murolith, elliptical, CA: plate, process, diagonal cross, R-UNITS: R-prominent, DETAILS: rim-unicyclic,
MetricsLith size: 6->8µm;
Sources: 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 Berriasian Stage (139.39-145.01Ma, top in Berriasian stage). Data source: Bown 2005
First occurrence (base): within Berriasian Stage (139.39-145.01Ma, base in Berriasian 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 adinfinitus, synonyms included - Rhagodiscus adinfinitus;
  • space-time plot :: Samples map :: Parent: Rhagodiscus


    Bown, P. R. (2005). 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

    Rahman, A. & Roth, P. H. (1991). Upper Jurassic calcareous nannofossils from the DSDP Site 534 in the Blake Bahama Basin, western North Atlantic. Eclogae Geologicae Helvetiae. 84: 765-789. gs :: view :: open


    Rhagodiscus adinfinitus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 16-7-2020

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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=11014 Go to Archive.is to create a permanent copy of this page - citation notes

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