Nannotax3 - ntax_mesozoic - Eiffellithus windii

Distinguishing features:
Parent taxon (Eiffellithus): Loxolith coccoliths with a prominent inner rim cycle that is birefringent and conspicuous in cross-polarised light; this cycle is broader than the outer rim cycle. The central area is spanned by variably-orientated cross-bars.
This taxon: Small to medium sized species of Eiffellithus (<6.4µm) with a narrow central-area almost filled by diagonal cross-bars.

Citation: Eiffellithus windii Applegate & Bergen, 1988

The highest occurrence of E. windii is not well constrained (?Lower Hauterivian) but there is a definite switch in dominance from E. windii-types to E. striatus-types in the uppermost Valanginian/lowermost Hauterivian.

Geological Range:
Last occurrence (top): in lower part of NC4 zone (20% up, 132.2Ma, in Hauterivian stage). Data source: Bown et al. 1998 (fig 5.1)
First occurrence (base): at base of BC4b subzone (0% up, 135.9Ma, in Valanginian stage). Data source: Bown et al. 1998 - sub-zonal marker, base of BC4b and CC3b

References:

Applegate, J. L. & Bergen, J. A. (1988). Cretaceous calcareous nannofossil biostratigraphy of sediments recovered from the Galicia Margin, ODP Leg 103. Proceedings of the Ocean Drilling Program, Scientific Results. 103: 293-348. gs O

Bown, P. R. & Concheyro, A. (2004). Lower Cretaceous calcareous nannoplankton from the Neuquen Basin, Argentina. In, Villa, G., Lees, J. A. & Bown, P. R. (eds) Calcareous Nannofossil Palaeoecology and Palaeocenographic Reconstructions, Proceedings of the INA9 conference, Parma 2002. Marine Micropaleontology . 52(1-4): 51-84. 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

Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Lower Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 86-131. gs O

Bralower, T. J., Monechi, S. & Thierstein, H. R. (1989). Calcareous nannofossil zonation of the Jurassic-Cretaceous boundary interval and correlation with the geomagnetic polarity timescale. Marine Micropaleontology. 14: 153-235. gs

Wind, F. H. & Cepek, P. (1979). Lower Cretaceous calcareous nannoplankton from DSDP Hole 397A (northwest African Margin). Initial Reports of the Deep Sea Drilling Project. 47A: 221-235. gs

Eiffellithus windii

References:

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