Distinguishing features:
Parent taxon (ntax_mesozoic): Mesozoic nannofossils - Cenozoic and extant taxa are in a separate module
This taxon: Placolith (or modified placolith) coccoliths with a distal cycle of clockwise-imbricating elements. R-units well developed, forming proximal and distal shield elements with opposite senses of imbrication; V-units typically form a narrow distal cycle near the inner edge of the shield.
Daughter taxa (time control age-window is: 0-800Ma)![]() | Granddaughter taxa | ||||
![]() | ![]() | ![]() | Watznaueriaceae Placoliths or modified placoliths with R-unit well developed, forming proximal and distal shield elements with opposite senses of imbrication; the V-unit typically forms a narrow distal cycle near the inner edge of the shield. Central-area structures are typically disjunct. Birefringent LM image, in which the V-unit cycle appears only as a thin, dark line. | Bussonius Cyclagelosphaera Diazomatolithus Lotharingius Watznaueria Ansulasphaera Bibreviconus Perchnielsenella |
Taxonomy:
Farinacci & Howe catalog pages: Watznaueriales [no catalog entry yet]
Distinguishing features:
Parent taxon (ntax_mesozoic): Mesozoic nannofossils - Cenozoic and extant taxa are in a separate module
This taxon: Placolith (or modified placolith) coccoliths with a distal cycle of clockwise-imbricating elements. R-units well developed, forming proximal and distal shield elements with opposite senses of imbrication; V-units typically form a narrow distal cycle near the inner edge of the shield.
Morphology:
: placolith, |
Lith size: 0->0µm; |
Geological Range:
Last occurrence (top): in lower part of Ypresian Stage (22% up, 54.2Ma, in Ypresian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Pliensbachian Stage (0% up, 190.8Ma, in Pliensbachian stage). Data source: Total of range of species in this database
Plot of occurrence data:
Bown, P. R. & Cooper, M. K. E. (1998). Jurassic. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 34-85. gs O Bown, P. R. (1987a). Taxonomy, evolution, and biostratigraphy of Late Triassic-Early Jurassic calcareous nannofossils. Special Papers in Palaeontology. 38: 1-118. gs Young, J. R. & Bown, P. R. (1997). Proposals for a revised classification system for calcareous nannoplankton. Journal of Nannoplankton Research. 19(1): 15-47. gs V OReferences:
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Watznaueriales compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 25-3-2023
Short stables page link: https://mikrotax.org/Nannotax3/index.php?id=11315 Go to Archive.is to create a permanent copy of this page - citation notes |
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