Distinguishing features:
Parent taxon (Watznaueriales): 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.
This taxon: 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.
Daughter taxa (time control age-window is: 0-800Ma)![]() | Granddaughter taxa | ||||
Regular placoliths | |||||
![]() | ![]() | ![]() | ![]() | Bussonius Elliptical watznaueriacean coccoliths with broad V-unit cycle, which results in a three tiered placolith structure. Moderately birefringent in XPL. | |
![]() | ![]() | ![]() | ![]() | Cyclagelosphaera Circular watznaueriacean coccoliths. | C. margerelii C. alta C. reinhardtii C. rotaclypeata C. shenleyensis C. argoensis C. brezae C. centrumelliptica C. deflandrei C. jiangii C. lacuna C. wiedmannii C. sp. |
![]() | ![]() | ![]() | ![]() | Diazomatolithus Modified watznaueriacean coccoliths with one conical/flaring (proximal) shield with elements joined along oblique sutures, and a smaller, flatter (distal) shield with the principle elements joined along near radial sutures. Usually circular with a central opening. | |
![]() | ![]() | ![]() | ![]() | Lotharingius Elliptical watznaueriacean coccoliths typically with central-area axial cross, with or without additional lateral bars. Cross usually spine bearing. Extinction figure with nearly straight arms. | L. hauffii L. frodoi L. umbriensis L. crucicentralis L. sigillatus L. barozii L. primitivus L. velatus L. sp. |
![]() | ![]() | ![]() | Watznaueria Elliptical watznaueriacean coccoliths with central-areas that are typically closed or narrow but may be spanned by transverse bar, bars or grill. Extinction figure with clearly inflected arms. | W. barnesiae W. bayackii W. fossacincta W. moshkovitzii W. ovata W. sp. large W. britannica W. reinhardtii W. biporta W. cynthae W. contracta W. okadai W. quadriradiata W. fasciata W. rawsonii C. baticlypeata W. sp. | |
Elevated taxa | |||||
![]() | ![]() | ![]() | ![]() | Ansulasphaera Watznaueriacean coccoliths with a tube-like/conical proximal shield. | |
![]() | Bibreviconus High, cylindrical morphology with a peg-like distal cycle; possibly the isolated central part of Cyclagelosphaera deflandrei specimens which have lost the shields. | ||||
Perchnielsenella Medium to large, barrel-shaped coccoliths that are highly-birefringent and seen in both side and plan view. |
Taxonomy:
Farinacci & Howe catalog pages: Watznaueriaceae [no catalog entry yet]
Distinguishing features:
Parent taxon (Watznaueriales): 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.
This taxon: 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.
Morphology:
Size:
Tags | LITHS: placolith, |
Metrics | 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 Reinhardt, P. (1964). Einige Kalkflagellaten-Gattungen (Coccolithophoriden, Coccolithineen) aus dem Mesozoikum Deutschlands. Monatsberichte der Deutschen Akademie der Wissenschaften zu Berlin. 6: 749-759. gs V O Rood, A. P., Hay, W. W. & Barnard, T. (1971). Electron Microscope Studies of Oxford Clay Coccoliths. Eclogae Geologicae Helvetiae. 64: 245-272. gs OReferences:
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Watznaueriaceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 23-5-2022
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=11314 Go to Archive.is to create a permanent copy of this page - citation notes |
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