Nannotax3 - ntax_mesozoic - Biscutum notaculum

Distinguishing features:
Parent taxon (Biscutum): Elliptical with broad shields with or without a prominent inner tube cycle; the central-area may be imperforate or narrow and vacant or spanned by a simple structure (plate, cross or bar).
This taxon: Small (3-5 µm), lenticular central area well-developed, almost closed.

Citation: Biscutum notaculum Wind & Wise in Wise & Wind, 1977

Geological Range:
Notes: FAD later in "extreme Tethyan" province, UC15b, (Burnett 1998)
Last occurrence (top): within Maastrichtian Stage (66.04-72.17Ma, top in Maastrichtian stage). Data source: Burnett 1998
First occurrence (base): in upper part of UC15a subzone (60% up, 79.9Ma, in Campanian stage). Data source: Burnett 1998, fig 6.4

References:

Burnett, J. A. (1998). Upper Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 132-199. gs O

Lees, J. A. (2007). New and rarely reported calcareous nannofossils from the Late Cretaceous of coastal Tanzania: outcrop samples and Tanzania Drilling Project Sites 5, 9 and 15. Journal of Nannoplankton Research. 29(1): 39-65. gs O

Pospichal, J. J. & Wise, S. W. (1990). Maestrichtian calcareous nannofossil biostratigraphy of Maud Rise ODP leg 113 sites 689 and 690, Weddell Sea. Proceedings of the Ocean Drilling Program, Scientific Results. 113: 465-487. gs

Thibault, N. (2010). Calcareous nannofossils from the boreal Upper Campanian- Maastrichtian chalk of Denmark. Journal of Nannoplankton Research. 31(1): 39-56. gs

Wind, F. H. & Wise, S. W. (1983). Correlation of upper Campanian-lower Maestrichtian calcareous nannofossil assemblages in drill and piston cores from the Falkland Plateau, southwest Atlantic Ocean. Initial Reports of the Deep Sea Drilling Project. 71: 551-563. gs

Wise, S. W. & Wind, F. H. (1977). Mesozoic and Cenozoic calcareous nannofossils recovered by DSDP Leg 36 drilling on the Falkland Plateau, south-west Atlantic sector of the Southern Ocean. Initial Reports of the Deep Sea Drilling Project. 36(269-491): -. gs O