Nannotax3 - ntax_cenozoic - Coronocyclus nitescens

Citation: Coronocyclus nitescens (Kamptner, 1963) Bramlette&Wilcoxon, 1967

Basionym: Umbilicosphaera nitescens Kamptner, 1963

Synonyms:

Cyclolithus prionion Deflandre & Fert 1954 - the type of this species is a TEM shadow which almost certainly is U. nitescens. However, the name has often been applied to Umbilicosphaera specimens (e.g Perch-Nielsen 1985 fig 24/11).
Coronocyclus prionion (Deflandre & Fert) Stradner in Stradner & Edwards,1968
Coronocyclus serratus Hay, Mohler and Wade, 1966 (NB Perch-Nielsen 1985, Shamrock & Watkins 2012 suggest using this name for specimens with a more serrated periphery)
Cyclococcolithus marginatus Jerkovic (1971) [my identification - JRY 2015]

Variants: Elliptical forms, with narrow rims, occur in NN5-6.

Taxonomic discussion: In the type description Kamptner's drawings resemble Umbilicosphaera rotula, however, the light micrograph is clearly C. nitescens as currently understood.

Distinguishing features:
Parent taxon (Coronocyclus): Coccoliths ring-shaped without discrete shields
This taxon: Ring-shaped coccoliths with open central-area. No clear shield development, spines on distal side. Strongly birefringent.

The coccolith morphology is rather complex and variable. In side view a central cyle of elements with stepped faces can be seen and in plan view this cycle forms the outmost cycle on both sides, sometimes this cycle develops spines. On the side assumed to be proximal the smaller of the faces on this outer cycle is directed anticlockwise; on the distal side it is directed clockwise. On the proximal side the inner cycles of elements show complex oblque sures, and do not develop spines. On the distal side the element sutures of the inner cycle are simpler and a large spine often develops on each element.

Geological Range:
Notes: FAD is poorly documented. Unambiguous speciemns have been illustrated by TEM from NP16/17 (Perch-Nielsen 1971) and Bown et al. (2007) record the species from Tanzania down to NP15. There are many earlier records in the Neptune databse but these may represent, at least in part, other species such as U. bramlettei. [Bown & Newsam 2017; my interpretation - JRY 2018].
LAD is a useful event in upper NN6/CNM9 according to both Raffi et al. (2006) and Boesiger et al. (2017), who give very similar placements for it.
Last occurrence (top): near top of NN6 zone (85% up, 12.1Ma, in Serravallian stage). Data source: Young 1998
First occurrence (base): within NP15 zone (42.87-46.29Ma, base in Lutetian stage). Data source: Bown et al., 2007

References:

Boesiger, T. M., de Kaenel, E., Bergen, J. A., Browning, E. & Blair, S. A. (2017). Oligocene to Pleistocene taxonomy and stratigraphy of the genus Helicosphaera and other placolith taxa in the circum North Atlantic Basin. Journal of Nannoplankton Research. 37(2-3): 145-175. gs O

Bown, P. R. & Dunkley Jones, T. (2012). Calcareous nannofossils from the Paleogene equatorial Pacific (IODP Expedition 320 Sites U1331-1334). Journal of Nannoplankton Research. 32(2): 3-51. gs O

Bown, P. R. (2005d). Palaeogene calcareous nannofossils from the Kilwa and Lindi areas of coastal Tanzania (Tanzania Drilling Project 2003-4). Journal of Nannoplankton Research. 27(1): 21-95. gs O

Bown, P. R., Dunkley-Jones, T. & Young, J. R. (2007). Umbilicosphaera jordanii Bown 2005 from the Paleogene of Tanzania: confirmation of generic assignment and a Paleocene origination for the family Calcidiscaceae. Journal of Nannoplankton Research. 29(1): 25-30. gs

Bramlette, M. N. & Wilcoxon, J. A. (1967b). Middle Tertiary calcareous nannoplankton of the Cipero section, Trinidad, W.I. Tulane Studies in Geology and Paleontology. 5: 93-131. gs O

da Gama, R. O. B. P. & Varol, O. (2013). New Late Oligocene to Miocene Species. Journal of Nannoplankton Research. 33(1): 1-12. gs

de Kaenel, E. & Villa, G. (1996). Oligocene-Miocene calcareous nannofossil biostratigraphy and paleoeecology from the Iberian Abyssal Plain. Proceedings of the Ocean Drilling Program, Scientific Results. 149: 79-145. gs O

Dunkley Jones, T., Bown, P. R. & Pearson, P. (2009). Exceptionally well preserved upper Eocene to lower Oligocene calcareous nannofossils (Prymnesiophycidae) from the Pande Formation (Kilwa Group), Tanzania. Journal of Systematic Palaeontology. 7(4): 359-411. gs

Hay, W. W., Mohler, H. P. & Wade, M. E. (1966). Calcareous nannofossils from Nal'chik (northwest Caucasus). Eclogae Geologicae Helvetiae. 59: 379-399. gs O

Jones, A. P. & Dunkley Jones, T. (2020). Middle Eocene to Early Oligocene calcareous nannofossils from the Nanggulan Formation, Java, Indonesia. Journal of Nannoplankton Research. 38(1): 57-79. gs

Kamptner, E. (1963). Coccolithineen-Skelettreste aus Tiefseeablagerungen des Pazifischen Ozeans. Annalen des Naturhistorischen Museums in Wien. 66: 139-204. gs O

Müller, C. (1974). Calcareous nannoplankton, Leg 25 (Western Indian Ocean). Initial Reports of the Deep Sea Drilling Project. 25: 579-633. gs

Perch-Nielsen, K. (1971c). Elektronenmikroskopische untersuchungen an Coccolithen und verwandten Formen aus dem Eozan von Danemark. Biologiske Skrifter, Kongelige Danske Videnskabernes Selskab. 18(3): 1-76. gs O

Perch-Nielsen, K. (1972). Remarks on Late Cretaceous to Pleistocene coccoliths from the North Atlantic. Initial Reports of the Deep Sea Drilling Project. 12: 1003-1069. gs

Perch-Nielsen, K. (1977). Albian to Pleistocene calcareous nannofossils from the Western South Atlantic, DSDP Leg 39. Initial Reports of the Deep Sea Drilling Project. 39: 699-823. gs O

Perch-Nielsen, K. (1985). Cenozoic calcareous nannofossils. In, Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge (1): 427-555. gs

Raffi, I. et al. (2006). A review of calcareous nannofossil astrobiochronology encompassing the past 25 million years. Quaternary Science Reviews. 25: 3113-3137. gs

Salomon, R. (1999). The Calcite Palace. Website - https://ina.tmsoc.org/galleries/CalcitePalace/index.htm. -. gs

Shamrock, J. L. & Watkins, D. K. (2012). Eocene calcareous nannofossil biostratigraphy and community structure from Exmouth Plateau, Eastern Indian Ocean (ODP Site 762). Stratigraphy. 9(1): 1-11. gs

Young, J. R. (1989). Observations on heterococcolith rim structure and its relationship to developmental processes. 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 . 1-20. gs

Young, J. R. (1998). Neogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 225-265. gs

Coronocyclus nitescens

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Sub-taxa & variants (time control age-window is: 0-800Ma)
				Coronocyclus nitescens subsp. latus Circular form with broad shield (>2 µm wide)