Eiffellithus keio

Classification: ntax_mesozoic -> Eiffellithales -> Eiffellithaceae -> Eiffellithus -> Eiffellithus keio
Sister taxa: E. eximius, E. lindiensis ⟩⟨ E. gorkae, E. keio, E. parallelus, E. pospichalii, E. turriseiffelii ⟩⟨ E. collis, E. equibiramus, E. parvus ⟩⟨ E. monechiae, E. praestigium, E. vonsalisiae, E. hancockii, E. paragogus ⟩⟨ E. primus, E. striatus, E. windii, E. sp.

Distinguishing features: Like E. turriseiffellii but with bifurcate tips to the cross-bars.


Citation: Eiffellithus keio Shamrock & Watkins 2009
Rank: Species
Taxonomic discussion: This form has a restricted range in the Late Albian and Cenomanian and so is clearly worth distinguishing.

Farinacci & Howe catalog pages: E. keio *

Distinguishing features: Like E. turriseiffellii but with bifurcate tips to the cross-bars.

Morphology: E. parallelus also has diagonal cross-bards and with bifurcet tips but in E. keio the bifurcations are larger, the cross is less regular, and the median extinction line less clear. They also have non-overlapping ranges.

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

Search data:
TagsLITHS: murolith, elliptical, CA: ca_disjunct, process, diagonal cross, closed, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent,
MetricsLith size: 0->0µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: Recorded by Shamrock and Watkins (2009) from Late Cenomanian only, but similar forms are docuemnted inthe ltierature from the Late Albian and Early Cenomanian - see images reassigned here to E. keio
Last occurrence (top): within Late Cenomanian Substage (93.90-95.47Ma, top in Cenomanian stage). Data source: Shamrock & Watkins 2009
First occurrence (base): within NC10a subzone (100.45-103.13Ma, base in Albian stage). Data source: images from Bown in Gale (2001) and Applegate & Bergen (1988)

Plot of occurrence data:


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 V O

Bown, P. R. (2001). Calcareous nannofossils of the Gault, Upper Greensand and Glauconitic Marl (Middle Albian-Lower Cenomanian) from the BGS Selborne boreholes, Hampshire. Proceedings of the Geologists' Association. 112: 223-236. 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

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


Eiffellithus keio compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 14-5-2021

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=11376 Go to Archive.is to create a permanent copy of this page - citation notes

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