Rutledge & Bown pl1 f 03.jpg
Burnett1998-6-04-13cd.jpg
Aguado et al 1999 f4b 28.jpg
Kanungo et al 2020 f5 27.JPG
Kanungo et al 2020 f5 28.JPG
Bown_etal_1998 EK 5-09-12.jpg
Bown_etal_1998 EK 5-09-13.jpg
Bown_in_Kennedy-2000_fig32-a^.JPG
Bown_in_Kennedy-2000_fig32-z.JPG
Aguado et al 2022 fig9-09.jpgDistinguishing 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: Small (<5µm), elliptical Rhagodiscus with a length/width ratio of <2.5, straight or slightly convex longer sides, and a central area filled with a granular plate which supports a hollow spine base.
| LITHS: murolith, elliptical, quadrate, CA: plate, process, CROSS-POLARS: rim-unicyclic, R-prominent, |
| Lith size: 3.5->5µm; Data source notes: original description & illustrated specimens |
Geological Range:
Last occurrence (top): within Cenomanian Stage (93.90-100.50Ma, top in Cenomanian stage). Data source: Bown et al. 1998
First occurrence (base): at base of BC18 zone (0% up, 120.7Ma, in Aptian stage). Data source: Bown et al. 1998 - zonal marker
Plot of occurrence data:
Aguado, R., Castro, J. M., Company, M. & de Gea, G. A. (1999). Aptian bioevents — an integrated biostratigraphic analysis of the Almadich Formation, Inner Prebetic Domain, SE Spain. Cretaceous Research. 20: 663-683. gs Aguado, R., Company, M., O'Dogherty, L., Sandoval, J. & Martinez, M. (2022). New insights into the Barremian–lower Aptian calcareous nannofossils of the Mediterranean Tethys: Chronostratigraphic and paleobiogeographic implications. Marine Micropaleontology. 173: 1-24. gs Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Lower Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 86-131. gs O Burnett, J. A. (1998). Upper Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 132-199. gs O Kanungo, S., Bown, P. R. & Gale, A. S. (2020). Cretaceous (Albian-Turonian) calcareous nannofossil biostratigraphy of the onshore Cauvery Basin, southeastern India. Cretaceous Research. 118 [2021]: 1-22. 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 Rutledge, D. & Bown, P. R. (1996). New names for old: taxonomic clarification of some Early Cretaceous nannofossil marker-species. Journal of Nannoplankton Research. 18(2): 53-59. gs References:
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Rhagodiscus gallagheri compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 9-8-2026
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=11021 Go to Archive.is to create a permanent copy of this page - citation notes |
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