Distinguishing features: A broadly elliptical Biscutum with a narrow central area spanned by a broad, hollow-spine-bearing, oblique transverse bar. Weakly bicyclic image in XPL.
Taxonomy:
Farinacci & Howe catalog pages: B. intermedium *
Distinguishing features: A broadly elliptical Biscutum with a narrow central area spanned by a broad, hollow-spine-bearing, oblique transverse bar. Weakly bicyclic image in XPL.
Search data:Tags | LITHS: placolith, elliptical, CA: ca_disjunct, process, bar, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent, |
Metrics | Lith size: 4.5->6µm; Data source notes: original description & illustrated specimens |
Geological Range:
Last occurrence (top): within NJ12a subzone (165.55-166.40Ma, top in Callovian stage). Data source: Bown & Cooper 1998
First occurrence (base): within NJ8a subzone (171.79-174.59Ma, base in Toarcian stage). Data source: Bown & Cooper 1998
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 Bown, P. R. (1987a). Taxonomy, evolution, and biostratigraphy of Late Triassic-Early Jurassic calcareous nannofossils. Special Papers in Palaeontology. 38: 1-118. gs Mattioli, E., Pittet, B., Young, J. R. & Bown, P. R. (2004a). Biometric analysis of Pliensbachian-Toarcian (Lower Jurassic) coccoliths of the family Biscutaceae: intra- and interspecific variability versus palaeoenvironmental influence. 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): 5-27. gs Menini, A., Mattioli, E., Spangenberg, J. E., Pittet, B. & Suan, G. (2018). New calcareous nannofossil and carbon isotope data for the Pliensbachian/Toarcian boundary (Early Jurassic) in the western Tethys and their paleoenvironmental implications. Newsletters on Stratigraphy. -. gsReferences:
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Biscutum intermedium compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 21-1-2021
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