Nannotax3 - ntax_mesozoic - Eiffellithus eximius

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: Large Eiffellithus with axial or sub-axial cross bars, longer cross-bar often with bifurcate tips

Citation: Eiffellithus eximius (Stover, 1966) Perch-Nielsen, 1968

Basionym: Clinorhabdus eximius Stover, 1966

Variants:

Eiffellithus augustus Bukry 1969 = Eiffelithus angustus Bukry (err. cit.) of Shamrock & Watkins 2009. Large form, with strongly bifurcating cross-bar tips (as opposed to E. eximius with simple cross-bar tips)
Eiffellithus digitatus Shamrock & Watkins 2009 - form with bifurcating cross-bar tips and intermediate cross-bar orientation
Eiffellithus perch-neilseniae Shamrock & Watkins 2009 - form with simple cross-bar tips and intermediate cross-bar orientiation
Eiffellithus nudus Shamrock & Watkins 2009 - smaller form (5-7 µm)

Shamrock and Watkins (2009) infer that forms with and without bifurcations are separate lineages and so divide E. eximus into forms with bifurcations (E. augustus) and those without (E. eximius) and further separate in each lineage forms with oblique crosses (20-45° from the long axis of the coccolith) and forms with axial crosses (0-20°) from the long axis). This leads to a scheme of four species. However, the forms intergrade and there appears to be remarkable parallelism in the evolution in the two sugested lineages. Likewise the smaller form E. nudus has virtually the same range as the larger typical E. eximius, so it is not clear that it is worth separating.

Most likely ancestor: Eiffellithus turriseiffelii - at confidence level 3 (out of 5). Data source: Verbeek 1977, Shamrock & Watkins 2009.

Geological Range:
Last occurrence (top): within UC15 zone (75.85-80.97Ma, top in Campanian stage). Data source: Burnett 1998 (zonal marker)
First occurrence (base): at base of UC8a subzone (0% up, 90.4Ma, in Turonian stage). Data source: Burnett 1998 (zonal marker), fig.6.3

References:

Bukry, D. (1969). Upper Cretaceous coccoliths from Texas and Europe. University of Kansas Paleontological Contributions, Articles. 51 (Protista 2): 1-79. gs O

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

Cepek, P. (1978). Mesozoic calcareous nannoplankton of the Eastern North Atlantic, Leg 41. Initial Reports of the Deep Sea Drilling Project. 41: 667-687. gs

Crux, J. A. (1980). A biostratigraphical study of Upper Cretaceous nannofossils from South-east England and North France. PhD thesis, University College London. -. gs

Hattner, J. G. & Wise, S. W. (1980). Upper Cretaceous calcareous nannofossil biostratigraphy of South Carolina. South Carolina Geology. 24: 41-117. gs

Hill, M. E. & Bralower, T. J. (1987). Early evolution, stratigraphy and taxonomy of Eiffellithus eximius and closely-related species. In, Stradner, H. , & Perch Nielsen, K, (eds) Proceedings of the INA Meeting, Vienna 1985. Abhandlungen der Geologischen Bundesanstalt . 39: 89-97. gs

Lees, J. A. & Bown, P. R. (2005). Upper Cretaceous calcareous nannofossil biostratigraphy, ODP Leg 198 (Shatsky Rise, Northwest Pacific Ocean). Proceedings of the Ocean Drilling Program, Scientific Results. 198: 1-60. gs

Perch-Nielsen, K. (1968). Der Feinbau und die Klassifikation der Coccolithen aus dem Maastrichtien von Danemark. Biologiske Skrifter, Kongelige Danske Videnskabernes Selskab. 16: 1-96. gs

Püttmann, T. & Mutterlose, J. (2019). Calcareous nannofossils from a Late Cretaceous nearshore setting. Journal of Nannoplankton Research. S4: 81-88. gs

Püttmann, T., Linnert, C., Dölling, B. & Mutterlose, J. (2018). Deciphering Late Cretaceous (Cenomanian to Campanian) coastline dynamics in the southwestern Münsterland (northwest Germany) by using calcareous nannofossils: Eustasy vs local tectonics,. Cretaceous Research. 87: 174-184. gs

Reinhardt, P. (1970). Synopsis der Gauttungen und Arten der mesozoischen Coccolithen und anderer kalkiger Nannofossilien. I. Freiberger Forschungshefte. C260: 5-32. gs

Romein, A. J. T., Willems, H. & Mai, H. (1996). Calcareous nannoplankton of the Geulhemmerberg K/T boundary section, Maastrichtian type area, the Netherlands. Geologie en Mijnbouw. 75: 231-238. gs

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

Shamrock, J. L. & Watkins, D. K. (2009). Evolution of the Cretaceous calcareous nannofossil genus Eiffellithus and its biostratigraphic significance. Cretaceous Research. 30(5): 1083-1102. gs

Stover, L. E. (1966). Cretaceous coccoliths and associated nannofossils from France and the Netherlands. Micropaleontology. 12(2): 133-167. gs

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

Varol, O. & Girgis, M. (1994). New taxa and taxonomy of some Jurassic to Cretaceous calcareous nannofossils. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 192: 221-253. gs

Eiffellithus eximius

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