Nannotax3 - ntax_mesozoic - Calcivascularis

Distinguishing features:
Parent taxon (Parhabdolithaceae): Murolith (protolith type) coccoliths with bicylic rims and central-areas spanned by an axial-cross or transverse bar bearing a broad, often long, spine.
This taxon: Protolith coccoliths with high rim, inner rim cycle not clearly developed, upper part of coccolith filled by mass of radiating elements.

Citation: Calcivascularis Wiegand 1984

Type species: Calcivascularis jansae Wiegand, 1984

Taxonomic discussion: Prins 1969 suggested evolution of M. irregularis (=C. jansae) from Mitrolithus elegans. Kristan-Tollmann (1988, 1995) suggested it should be placed in Eoconusphaera, and Bown & Cooper 1989 noted similarities with Conusphaera and Eoconusphaera. Recent practice has tended to be to use the genus Calcivascularis whilst noting the strong similarities to Eoconusphaera

Geological Range:
Last occurrence (top): at top of Kimmeridgian Stage (100% up, 149.2Ma, in Tithonian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within NJT2b subzone (194.83-199.46Ma, base in Sinemurian stage). Data source: Total of ranges of species in this database

References:

Bergen, J. A., Boesiger, T. M. & Pospichal, J. J. (2014). Low-latitude Oxfordian to Early Berriasian nannofossil biostratigraphy and its application to the subsurface of Eastern Texas. In, Hammes, U. & Gale, J. (eds) Geology of the Haynesville Gas Shale in East Texas and West Louisiana, U.S.A. American Association of Petroleum Geologists, Memoirs . 105: 69-102. gs

Bown, P. R. & Cooper, M. K. E. (1989a). Conical nannofossils in the Mesozoic. In, Crux, J. A. & van Heck, S. E. (eds) Nannofossils and their applications: Proceedings of the 2nd INA Conference, London 1987. British Micropalaeontological Society Publication Series . 98-106. gs

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

Kristan-Tollmann, E. (1988). Coccolithen aus den Älteren Allgäuschichten (Alpiner Lias, Sinemur) von Timor, Indonesien. Geologisch-Paläontologische Mitteilungen Innsbruck. 15: 71-83. 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

Wiegand, G. E. (1984). Two new genera of calcareous nannofossils from the Lower Jurassic. Journal of Paleontology. 58(4): 1151-1155. gs

Young, J. R., Teale, C. T. & Bown, P. R. (1986). Revision of the stratigraphy of the Longobucco Group (Liassic, southern Italy); based on new data from nannofossils and ammonites. Eclogae Geologicae Helvetiae. 79(1): 117-135. gs

Missing or ambiguous references: Kristan-Tollmann 1995;

Daughter taxa (time control age-window is: 0-800Ma)
				Calcivascularis cassidyi Small Calcivascularis with a high number of rim elements, sub-parallel walls, and a circular horizontal outline.
				Calcivascularis jansae Very tall, narrow, steeply sloping rim with a central area filled with a mass of radially arranged elements. Most commonly seen in side view.
				Calcivascularis sp.

Calcivascularis

References:

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