Distinguishing features: Parent taxon (Eiffellithales): Murolith coccoliths with an upper/outer cycle of clockwise-imbricate V-units and a lower/inner cycle of R-units.
This taxon: Eiffelithales with V-units forming most of rim (R-units typically thin plates on proximal surface, so LM images are typically unicyclic. Central-areas typically filled by a plate of granular calcite. The central structure may be spine-bearing, perforate or massive.
Daughter taxa (time control age-window is: 0-800Ma)
Granddaughter taxa
Percivalia Loxolith coccoliths with narrow outer cycle and wide central area filled with a granular plate or bridge, multiple concentric cycles seen on proximal face.
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.
Distinguishing features: Parent taxon (Eiffellithales): Murolith coccoliths with an upper/outer cycle of clockwise-imbricate V-units and a lower/inner cycle of R-units.
This taxon: Eiffelithales with V-units forming most of rim (R-units typically thin plates on proximal surface, so LM images are typically unicyclic. Central-areas typically filled by a plate of granular calcite. The central structure may be spine-bearing, perforate or massive.
Search data:
Tags
LITHS: murolith,
Metrics
Lith size: 0->0µm;
The morphological data given here can be used on the advanced search page. See also these notes
Geological Range: Last occurrence (top): at top of Maastrichtian Stage (100% up, 66Ma, in Danian stage). Data source: Total of range of species in this database First occurrence (base): at base of Tithonian Stage (0% up, 152.1Ma, in Kimmeridgian stage). Data source: Total of range of species in this database
Plot of occurrence data:
Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Neptune data: this is a higher taxon page so Neptune data is not plotted. For the customisable plot option go to a genus page Parent: Eiffellithales
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
Rhagodiscaceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 18-10-2021
Comments
(0)