Distinguishing features:
Parent taxon (Triscutum): Three-shielded placoliths with a wide central-area spanned by a proximal net or grill.
This taxon: Medium (7-8 µm)Triscutum with a wide central area spanned by a net formed from numerous, (~80) thin lateral bars.
Taxonomy:
Farinacci & Howe catalog pages: P. expansus *
Distinguishing features:
Parent taxon (Triscutum): Three-shielded placoliths with a wide central-area spanned by a proximal net or grill.
This taxon: Medium (7-8 µm)Triscutum with a wide central area spanned by a net formed from numerous, (~80) thin lateral bars.
Search data:
LITHS: placolith, elliptical, cylindrical, hollow, CA: ca_disjunct, grill, |
Lith size: 7->8µm; Data source notes: illustrated specimens |
Geological Range:
Last occurrence (top): within Early Oxfordian Substage (159.40-161.50Ma, top in Oxfordian stage). Data source: Bown & Cooper 1998
First occurrence (base): within Late Bathonian Substage (165.30-166.00Ma, base in Bathonian 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 O Dockerill, H. J. (1987). Triscutum, a distinctive new coccolith from the Jurassic. Bulletin des Centres de Recherches Exploration-Production Elf-Aquitaine. 11: 127-131. gs Grün, W. & Zweili, F. (1980). Das kalkige Nannoplankton der Dogger-Malm-Grenze im Berner Jura bei Liesberg (Schweiz). Jahrbuch der Geologischen Bundesanstalt. 123: 231-341. gs Medd, A. W. (1979). The Upper Jurassic coccoliths from the Haddenham and Gamlingay boreholes (Cambridgeshire, England). Eclogae Geologicae Helvetiae. 72: 19-109. gs OReferences:
Triscutum expansus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 19-9-2024
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=11254 Go to Archive.is to create a permanent copy of this page - citation notes |
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