Taxonomy:
These two species were described from LM side views of Toarcian Calyculus. No details of the base are visible so they cannot be correlated wth the species of Goy 1979.
Distinguishing features:
Parent taxon (Calyculus): High, broad, flaring distal-shield composed of radial, non-imbricating elements, and a proximal-shield which is often reduced to a simple, narrow cycle of elements; central-area structures are highly variable, including numerous bars, concentric structures, nets and grills.
This taxon: Specimens not identified to species level. NB Late Jurassic specimens are grouped separately.
Farinacci & Howe catalog pages: P. fistulatus * , C. fistulatus *
Morphology:
Lith size: 0->0µm; |
Geological Range:
Last occurrence (top): within Toarcian Stage (174.70-184.20Ma, top in Toarcian stage). Data source:
First occurrence (base): within (-Ma, base in "Holocene" stage). Data source:
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 Bown, P. R. (1987a). Taxonomy, evolution, and biostratigraphy of Late Triassic-Early Jurassic calcareous nannofossils. Special Papers in Palaeontology. 38: 1-118. gs Bown, P. R. (1987b). The structural development of Early Mesozoic coccoliths and its evolutionary and taxonomic significance. Abhandlungen der Geologischen Bundesanstalt. 39: 33-49. 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 Crux, J. A. (1987b). Early Jurassic calcareous nannofossil biostratigraphic events. Newsletters on Stratigraphy. 17: 79-100. gs Crux, J. A. (1987a). Concerning dimorphism in Early Jurassic coccoliths and the origin of the genus Discorhabdus Noël 1965. Abhandlungen der Geologischen Bundesanstalt. 39: 51-55. gs Medd, A. W. (1979). The Upper Jurassic coccoliths from the Haddenham and Gamlingay boreholes (Cambridgeshire, England). Eclogae Geologicae Helvetiae. 72: 19-109. gs O 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. -. gs Prins, B. (1969). Evolution and stratigraphy of cocolithinids from the Lower and Middle Lias. In, Bronnimann, P. & Renz, H. H. (eds) Proceedings of the First International Conference on Planktonic Microfossils, Geneva 1967. E. J. Brill, Leiden 547-558. gs Sandoval, J., et al. (2012). The Toarcian in the Subbetic basin (southern Spain): bio-events (ammonite and calcareous nannofossils) and carbon-isotope stratigraphy. Palaeogeography Palaeoclimatology Palaeoecology. 342-3: 40-63. gs Missing or ambiguous references: Goy 1979; References:
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Calyculus sp. compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 21-5-2025
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10195 Go to Archive.is to create a permanent copy of this page - citation notes |
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