Nannotax3 - ntax_cenozoic - Toweius occultatus

Citation: Toweius occultatus (Locker, 1967) Perch-Nielsen, 1971

Basionym: Coccolithus occultatus Locker, 1967

Synonyms: Coccolithus petrinus Stradner, 1969 [my identification - JRY 2015]

Distinguishing features:
Parent taxon (Toweius): Elliptical to circular prinsiacean placoliths with central areas that are typically spanned by a proximal net and/or distal conjunct nets or bars. Typically medium sized.
This taxon: Medium to large with 2 large openings in the central area.

Medium to large; elliptical to sub-circular; central area spanned by a fine proximal net and 2, broad conjunct transverse bars that taper towards the centre. Only the tranverse bars are visible in LM, they extend from the proximal surface to the distal surface.

Type material length: 6.5-9.0 microns.

The evolutionary transition from T. eminens to T. occultatus is described in detail by Bybell & Self-Trail (1995), and more briefly by Romein (1979).

Most likely ancestor: Toweius eminens - at confidence level 4 (out of 5). Data source: Bybell & Self-Trail (1995, p.11, fig. 23).

Geological Range:
Last occurrence (top): within NP13 zone (49.11-50.5Ma, top in Ypresian stage). Data source: Perch-Nielsen 1985b
First occurrence (base): within NP9 zone (55.86-57.21Ma, base in Thanetian stage). Data source: Perch-Nielsen 1985

References:

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. (2010). Calcareous nannofossils from the Paleocene/Eocene Thermal Maximum interval of southern Tanzania (TDP Site 14). Journal of Nannoplankton Research. 31(1): 11-38. gs O

Bybell, L. M. & Self-Trail, J. (1995). Evolutionary, biostratigraphic and taxonomic study of calcareous nanofossils from a continuous Palaeocene-Eocene boundary section in New Jersey. U.S. Geological Survey, Professional Paper. 1554: 1-36. gs O

Locker, S. (1967c). Neue, statigraphisch wichtige Coccolithophoriden (Flagellata) aus dem norddeutschen Alttertiar. Monatsberichte der Deutschen Akademie der Wissenschaften zu Berlin. 9(9-10): 758-769. gs

Müller, C. (1979). Calcareous nannofssils from the North Atlantic (Leg 48). Initial Reports of the Deep Sea Drilling Project. 48: 589-639. gs

Perch-Nielsen, K. (1971). 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. (1985). Cenozoic calcareous nannofossils. In, Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge 427-555. gs

Perch-Nielsen, K., Sadek, A., Barakat, M. G. & Teleb, F. (1978). Late Cretaceous and Early Tertiary Calcareous nannofossil and Planktonic foraminifera zones from Egypt. Actes du VI Colloque Africain de Micropaléontologie - Tunis 1974. Annales des Mines et de la Géologie Tunis. 28: 337-403. gs

Self-Trail, J. (2011). Paleogene Calcareous Nannofossils of the South Dover Bridge core, Southern Maryland (USA). Journal of Nannoplankton Research. 32(1): 1-28. gs

Self-Trail, J. M., Powars, D. S., Watkins, D. K. & Wandless, G. A. (2012). Calcareous nannofossil assemblage changes across the Paleocene–Eocene Thermal Maximum: Evidence from a shelf setting. Marine Micropaleontology. 92–93: 61-80. gs

Shepherd, C. L. & Kulhanek, D. K. (2016). Eocene nannofossil biostratigraphy of the mid-Waipara River section, Canterbury Basin, New Zealand. Journal of Nannoplankton Research. 36(1): 33-59. gs O

Varol, O. (1998). Palaeogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 200-224. gs

Toweius occultatus

References:

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