Taxonomy:
Distinguishing features: Pontosphaera with elevated, birefringent rim and a thin, low birefringence plate with many small perforations.
Farinacci & Howe catalog pages: P. alta *
Search data:Tags | LITHS: murolith, elliptical, CA: ca_conjunct, pores, CROSS-POLARS: rim-unicyclic, V-prominent, R-prominent, |
Metrics | Lith size: 8->15µm; Data source notes: lith size from OD & illustrated specimens |
Geological Range:
Last occurrence (top): within NP21 zone (32.92-34.44Ma, top in Rupelian stage). Data source: Dunkley Jones et al., 2009
First occurrence (base): within NP19-20 zone (34.44-36.97Ma, base in Priabonian stage). Data source: Dunkley Jones et al., 2009
Plot of occurrence data:
Bown, P. R. & Newsam, C. (2017). Calcareous nannofossils from the Eocene North Atlantic Ocean (IODP Expedition 342 Sites U1403–1411). Journal of Nannoplankton Research. 37(1): 25-60. gs V O Dunkley Jones, T., Bown, P. R. & Pearson, P. (2009). Exceptionally well preserved upper Eocene to lower Oligocene calcareous nannofossils (Prymnesiophycidae) from the Pande Formation (Kilwa Group), Tanzania. Journal of Systematic Palaeontology. 7(4): 359-411. gs Jones, A. P. & Dunkley Jones, T. (2020). Middle Eocene to Early Oligocene calcareous nannofossils from the Nanggulan Formation, Java, Indonesia. Journal of Nannoplankton Research. 30(1): 57-79. gs V O Roth, P. H. (1970). Oligocene calcareous nannoplankton biostratigraphy. Eclogae Geologicae Helvetiae. 63: 799-881. gs V OReferences:
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Pontosphaera alta compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 26-2-2021
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