Rhagodiscaceae


Classification: Mesozoic -> Eiffellithales -> Rhagodiscaceae
Sister taxa: Chiastozygaceae, Eiffellithaceae, Rhagodiscaceae,

Distinguishing features: Murolith (loxolith type) coccoliths with dominant distal/outer cycles and central-areas typically filled by a plate of granular calcite. The central structure may be spine-bearing, perforate or massive. LM images are typically unicyclic.


Daughter taxa: (blue => in age window 0-800Ma) Granddaughter taxa
Muroliths (loxolith type) with high, narrow rim and wide central-area filled by a large, domed, granular mass.

Loxolith coccoliths with narrow outer cycle and wide central area filled with a granular plate or bridge.

Loxolith coccoliths with low rim and central-area filled by a granular plate which may be perforate and spine-bearing. Rim image is typically unicyclic in XPL.

Solid, truncated-cone-shaped nannolith (possibly a holococcolith), with distinct outer rim and banded core.

Taxonomy:

Citation: Rhagodiscaceae Hay, 1977
Rank: Family
Type species: Rhagodiscus Reinhardt, 1967.

Farinacci & Howe catalog pages: Rhagodiscaceae [no catalog entry yet]

Distinguishing features: Murolith (loxolith type) coccoliths with dominant distal/outer cycles and central-areas typically filled by a plate of granular calcite. The central structure may be spine-bearing, perforate or massive. LM images are typically unicyclic.

Geological Range:
Last occurrence (top): at top of Maastrichtian Stage (100% up, 66Ma, in Maastrichtian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Tithonian Stage (0% up, 152.1Ma, in Tithonian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Early Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 86-131. gs

Hay, W. W. (1977). Calcareous nannofossils. In, Ramsay, A. T. S. (ed.) Oceanic Micropalaentology. Academic Press, London 1055-1200. gs


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Rhagodiscaceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 22-11-2019

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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=11011 Go to Archive.is to create a permanent copy of this page - citation notes



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