Nannotax3 - ntax_mesozoic - Eiffellithus hancockii

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: Minute loxolith with very narrow central area filled with short axial cross bars.

Citation: Eiffellithus? hancockii Burnett, 1997

Taxonomic discussion: Only tentatively included in Eiffellithus by Burnett (1997). Watkins & Bergen (2003 p.232) argued that this species was misplaced in Eiffelithus but they did not propose an alternative combination.

A small- to medium-sized, elliptical coccolith with a thick bicyclic rim. The outer rim is relatively wide and dark and the inner rim is broader and highly birefringent. A very small, axial cross completely occupies the central area of the coccolith. [Burnett 1997]

Geological Range:
Last occurrence (top): within Middle Cenomanian Substage (95.50-96.24Ma, top in Cenomanian stage). Data source: Burnett 1997
First occurrence (base): within Late Albian Substage (100.50-107.59Ma, base in Albian stage). Data source: Burnett 1997

References:

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

Burnett, J. A. (1997c). New species and new combinations of Cretaceous nannofossils and a note on the origin of Petrarhabdus (Deflandre) Wise & Wind. Journal of Nannoplankton Research. 19(2): 133-146. gs

Gale, A. S., Kennedy, W. J., Burnett, J. A., Caron, M. & Kidd, B. E. (1996). The Late Albian to Early Cenomanian succession at Mont Risou, near Rosans (Drôme, SE France): an integrated study (ammonites, inoceramids, planktonic foraminifera, nannofossils, oxygen and carbon isotopes). Cretaceous Research. 17: 515-606. gs

Gale, A. S. et al. (2011). The uppermost Middle and Upper Albian succession at the Col de Palluel, Hautes-Alpes, France: An integrated study (ammonites, inoceramid bivalves, planktonic foraminifera, nannofossils, geochemistry, stable oxygen and carbon isotopes, cyclostratigraphy). Cretaceous Research. 32: 59-130. gs

Watkins, D. K. & Bergen, J. A. (2003). Late Albian adaptive radiation in the calcareous nannofossil genus Eiffelithus. Micropaleontology. 49(3): 231-252. gs

Eiffellithus hancockii

References:

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