Nephrolithus frequens


Classification: ntax_mesozoic -> Podorhabdales -> Axopodorhabdaceae -> Nephrolithus -> Nephrolithus frequens
Sister taxa: N. corystus, N. frequens, N. sp.

Distinguishing features: Central area with 2-15 perforations each surrounded by neat rings of rhombic elements


Daughter taxa (time control age-window is: 0-800Ma)
Nephrolithus frequens subsp. frequens
Forms of N. frequens, with >2 holes in the central area (usually larger than N. frequens miniporus)
Nephrolithus frequens subsp. miniporus
Reniform to elliptical subspecies of N. frequens with only two holes within the central area.

Taxonomy:

Citation: Nephrolithus frequens Górka, 1957
Rank: Species
Synonyms: List from Pospichal & Wise (1990), same list given by Prins & Sissingh, in Sissingh (1977) 

Farinacci & Howe catalog pages: N. frequens + * , N. gorkae * , N. furcatus * , N. trientis * , N. barbarae *

Distinguishing features: Central area with 2-15 perforations each surrounded by neat rings of rhombic elements

Search data:
TagsLITHS: placolith, asymmetric, CA: ca_disjunct, plate, pores, closed, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent,
MetricsLith size: 4->8µm;
Data source notes: range of sub-species
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: FAD highly diachronous, occuring UC20b in N. Europe;  at base UC17 in the Tethyan Province; and in UC15e in the "extreme Tethyan province (Burnett 1998). Its regional FAD can be a valuable marker within the Maastrichtian but needs to be used with caution, Watkins et al. 1996, Pospichal & Wise 1990.
Last occurrence (top): within Late Maastrichtian Substage (66.04-69.91Ma, top in Maastrichtian stage). Data source: Burnett 1998
First occurrence (base): in mid part of UC15d subzone (50% up, 76.4Ma, in Campanian stage). Data source: Burnett 1998

Plot of occurrence data:

References:

Åberg, M. (1966). Electron microscope studies on Nephrolithus (Coccolithophoraceae). Stockholm Contributions in Geology. 13: 63-67. gs

Burnett, J. A. (1998). Upper Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 132-199. gs V O

Górka, H. (1957). Les Coccolithophoridés du Maestrichtien supérieur de Pologne. Acta Palaeontologica Polonica. 2: 239-284. gs V O

Pospichal, J. J. & Wise, S. W. (1990b). Maestrichtian calcareous nannofossil biostratigraphy of Maud Rise ODP leg 113 sites 689 and 690, Weddell Sea. Proceedings of the Ocean Drilling Program, Scientific Results. 113: 465-487. gs V O

Sissingh, W. (1977). Biostratigraphy of Cretaceous calcareous nannoplankton. Geologie en Mijnbouw. 65(1): 37-65. gs

Watkins, D. K., Wise, S. W., Pospichal, J. J. & Crux, J. (1996). Upper Cretaceous calcareous nannofossil biostratigraphy and paleoceanography of the Southern Ocean. In, Moguilevsky, A. & Whatley, R. (eds) Microfossils and Oceanic Environments. University of Wales, Aberystwyth Press 355-381. gs V O


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Nephrolithus frequens compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 15-4-2021

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10798 Go to Archive.is to create a permanent copy of this page - citation notes



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