Distinguishing features:
Parent taxon (Tubodiscus): Tubodiscids with high and birefringent proximal collar cycle and wide central-area. Rim image is clearly bicyclic in XPL.
This taxon: Large (8-16 µm) with wide central area. Inner and outer rim cycles of similar width.
Taxonomy:
Farinacci & Howe catalog pages: W. jurapelagicus *
Distinguishing features:
Parent taxon (Tubodiscus): Tubodiscids with high and birefringent proximal collar cycle and wide central-area. Rim image is clearly bicyclic in XPL.
This taxon: Large (8-16 µm) with wide central area. Inner and outer rim cycles of similar width.
Morphology:
LITHS: placolith, elliptical, CA: vacant, CROSS-POLARS: R-prominent, V-prominent, rim-bicyclic, |
Lith size: 8->16µm; Data source notes: original description & illustrated specimens |
Geological Range:
Last occurrence (top): within Barremian Stage (121.40-126.50Ma, top in Barremian stage). Data source: Bown et al. 1998
First occurrence (base): within Late Berriasian Substage (137.70-139.90Ma, base in Berriasian stage). Data source: Bown et al. 1998
Plot of occurrence data:
Bown, P. R. & Concheyro, A. (2004). Lower Cretaceous calcareous nannoplankton from the Neuquen Basin, Argentina. In, Villa, G., Lees, J. A. & Bown, P. R. (eds) Calcareous Nannofossil Palaeoecology and Palaeocenographic Reconstructions, Proceedings of the INA9 conference, Parma 2002. Marine Micropaleontology . 52(1-4): 51-84. gs 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 O Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Lower Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 86-131. gs O Bralower, T. J., Monechi, S. & Thierstein, H. R. (1989). Calcareous nannofossil zonation of the Jurassic-Cretaceous boundary interval and correlation with the geomagnetic polarity timescale. Marine Micropaleontology. 14: 153-235. gs Roth, P. H. (1973). Calcareous nannofossils: Leg 17 of the Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project. 17: 695-795. gs O Worsley, T. R. (1971). Calcareous nannofossil zonation of Upper Jurassic and Lower Cretaceous sediments from the Western Atlantic. In, Farinacci, A. (ed.) Proceedings of the Second Planktonic Conference Roma 1970. Edizioni Tecnoscienza, Rome 2: 1301-1321. gs OReferences:
Tubodiscus jurapelagicus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 6-11-2024
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=11276 Go to Archive.is to create a permanent copy of this page - citation notes |
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