Distinguishing features: Murolith coccoliths with V-units forming a narrow imbricate outer wall and R-units extending to form a wide inner rim cycle or plate. Most with a spine bearing central cross.
| Daughter taxa: (blue => in age window 0-800Ma) | Granddaughter taxa | ||||
| | | | Murolith coccoliths with rim formed of outer cycle of imbricate V-units and variably developed inner cycle of R-units. Disjunct central bar or cross, usually supporting a spine. | |
| | | | V-units form narrow outer rim; R-units form broad inner rim or plate. Almost all with a central spine-bearing cross. | |
| | | | 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. | |
Taxonomy:
Farinacci & Howe catalog pages: Eiffellithales [no catalog entry yet]
Distinguishing features: Murolith coccoliths with V-units forming a narrow imbricate outer wall and R-units extending to form a wide inner rim cycle or plate. Most with a spine bearing central cross.
Geological Range:
Last occurrence (top): at base of Ypresian Stage (1% up, 55.9Ma, in Ypresian stage). Data source: Total of range of species in this database
First occurrence (base): in mid part of Norian Stage (50% up, 218.9Ma, in Norian stage). Data source: Total of range of species in this database
Plot of occurrence data:
Bown, P. R. (1998b). Triassic. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 29-33. gs Rood, A. P., Hay, W. W. & Barnard, T. (1971). Electron Microscope Studies of Oxford Clay Coccoliths. Eclogae Geologicae Helvetiae. 64: 245-272. gsReferences:
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Eiffellithales compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 21-1-2020
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