Kokia borealis


Classification: Mesozoic -> Braarudosphaerales -> Other nannoliths with tangential c-axes -> Kokia -> Kokia borealis
Sister taxa: K. borealis, K. curvata, K. kayae, K. stellata, K. sp.,

Distinguishing features: Stellate, multiradiate, rosette-shaped nannolith constructed from eight to ten single crystal-unit radial rays that show low birefringence under XPL. C-axes tangential.


Taxonomy:

Citation: Kokia borealis Perch-Nielsen, 1988
Rank: Species

Farinacci & Howe catalog pages: Kokia borealis *

Distinguishing features: Stellate, multiradiate, rosette-shaped nannolith constructed from eight to ten single crystal-unit radial rays that show low birefringence under XPL. C-axes tangential.


Morphology remarks: Mostly reported from the Berriasian to earliest Valanginian of the Boreal North Sea Basin (Bown et al., 1998), but Lozar and Tremolada (2003) recorded it (unillustrated) from the Hauterivian of the northwest Pacific Ocean. It was found in one Berriasian sample (Subzone NK2a) from Shatsky Rise, Pacific Ocean (Bown, 2005).
The elements show tangential c-axis orientations (van Niel 1994) suggesting possible affinites with the Braarudosphaeraceae or Polycyclolithaceae.

Geological Range:
Last occurrence (top): within Early Valanginian Substage (136.41-139.39Ma, top in Valanginian stage). Data source: Bown et al. 1998
First occurrence (base): within Berriasian Stage (139.39-145.01Ma, base in Berriasian stage). Data source: Bown et al. 1998

Plot of occurrence data:

  • Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
  • Note to users in China - the diagram may not plot unless you use a VPN since I use google services on the website. If this is a problem please contact me 谢谢.
  • Taxon plotted: Kokia borealis, synonyms included - Kokia borealis;
  • space-time plot :: Samples map :: Parent: Kokia

    References:

    Bown, P. R. (2005c). Early to Mid-Cretaceous Calcareous Nannoplankton from the Northwest Pacific Ocean, Leg 198, Shatsky Rise. Proceedings of the Ocean Drilling Program. Scientific Results. 198: 1-82. gs

    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

    Jeremiah, J. (2001). A Lower Cretaceous nannofossil zonation for the North Sea Basin. Journal of Micropalaeontology. 20: 45-80. gs

    Lozar, F. & Tremolada, F. (2003). Calcareous nannofossil biostratigraphy of Cretaceous sediments recovered at ODP Site 1149 (Leg 185, Nadezhda Basin, Western Pacific). In: Proceedings of the Ocean Drilling Program, Scientific Results Volume 185. Ludden, J.N., Plank, T. and Escutia, C. (Editors), Ocean Drilling Program, College Station. 185: 21. Proceedings of the Ocean Drilling Program. Scientific Results. 185: 1-21. gs

    Perch-Nielsen, K. (1988). New Lower Cretaceous calcareous nannofossil species from England. INA Newsletter. 10(1): 30-37. gs

    van Niel, B. E. (1994b). Scanning electron micrographs of the genus Kokia (incertae sedis). Journal of Nannoplankton Research. 16(2): 75-77. gs

    Varol, O. & Girgis, M. (1994). New taxa and taxonomy of some Jurassic to Cretaceous calcareous nannofossils. Neues Jahrbuch für Geologie und Paläontologie Abhandlungen. 192: 221-253. gs


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    Kokia borealis compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 17-11-2019

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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10543 Go to Archive.is to create a permanent copy of this page - citation notes



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