Eiffellithus


Classification: Mesozoic -> Eiffellithales -> Eiffellithaceae -> Eiffellithus
Sister taxa: Diloma, Eiffellithus, Helicolithus, Tegumentum,

Distinguishing features: 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.


Daughter taxa: (blue => in age window 0-800Ma)
Late Cretaceous species with (sub)axial cross
Large Eiffellithus with sub-axial cross bars,longer cross-bar with bifurcate tips
Small (3-5 µm) Eiffellithus, cross-bars axially aligned, terminations simple
Late Cretaceous species with diagonal cross
Cross-bars diagonal, small, cross isolated in centre of coccolith, terminations simple
Diagonal cross with bifurcate ray tips and axial suture
Large (holotype 11µm) Eiffellithus with thick diagonal cross-bars
Eiffellithus with nearly symmetrical diagonal cross bars.
Albian-Cenomanian species with diagonal cross

Medium, normally elliptical, eiffellithid; arms form symmetrical diagonal cross; each arm composed of two, subequal, rectangular, disjunct crystal-units with blunt distal tips divided by a prominent central suture.
Medium eiffellithid with stem base of four trapezohedral arms forming a symmetrical diagonal cross whose outline is roughly rectangular.
Albian-Cenomanian species with (sub)axial cross
Medium sized Eiffellithus with cross bars aligned within 20° of the major axes (within 10° according to Watkins & Bergen 2003).
Medium eiffellithid with sub-axial cross (rotated 10-20°). Struts with central suture  and clavate to blunt tips.
Medium to large eiffellithid with asymmetrical cross (20-35° from axis). Arms divided by central suture and with blunt to pointed tips.
Minute loxolith with very narrow central area filled with short axial cross bars.
Bicyclic loxolith with broad, bright inner cycle, diamond-shaped central-area and cross bars that are relatively narrow, parallel-sided and lack any striations or median extinction line.
pre-Aptian species
Small to medium sized Eiffellithus coccolith with an axial cross.
Medium to large species of Eiffellithus (>6.4µm length) with a wide central-area spanned by diagonal cross-bars.
Small to medium sized species of Eiffellithus (<6.4µm) with a narrow central-area almost filled by diagonal cross-bars.
Specimens not identified to species level

Taxonomy:

Citation: Eiffellithus Reinhardt, 1965
Rank: Genus
Type species: Zygolithus turriseiffelii Deflandre in Deflandre & Fert, 1954
Synonyms: Clinorhabdus Stover 1966

Farinacci & Howe catalog pages: Eiffellithus + + * , Clinorhabdus * , Eiffellithus casulus * , Eiffellithus digitatus * , Eiffellithus keio * , Eiffellithus nudus * , Eiffellithus perch-nielsenae * , Eiffellithus phantasma *

Distinguishing features: 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.


Morphology remarks: Eiffellithus is used for earliest Cretaceous (E. primus, E. striatus, E. windii) and mid-late Cretaceous taxa that have very similar morphologies but which may not be closely related. The Early Cretaceous species were described by Applegate & Bergen (1988). The principal late Creteceous eiffellithids, E. eximius, E. monechiae and E. turriseiffelii are considered members of a meaningful taxonomic clade, which probably originated from Staurolithites (see, e.g. Watkins & Bergen, 2003). However, the relationship between these eiffellithids and a number of similar mid-Cretaceous coccoliths, e.g. Helicolithus spp.,  Eiffellithus paragogus (Staurolithites glabra of some authors) and Eiffellithus hancockii, is uncertain.

The mid-Cretaceous adaptive radiation of the eiffellithids is reviewed and documented in Watkins & Bergen (2003), including description of four species (E. praestigium, E. vonsalisiae, E. equibiramus, and E. parvus).

Additional species have been described by Shamrock & Watkins (2009) based on detailed morphometric analysis., espcially of size, cross-bar alignment and cross-bar terminations. These have not been included on the site yet but are listed here - and descriptions are given in the Farinacci catalog.

Geological Range:
Last occurrence (top): at top of Maastrichtian Stage (100% up, 66Ma, in Maastrichtian stage). Data source: Total of range of species in this database
First occurrence (base): in lower part of Berriasian Stage (26% up, 143.5Ma, in Berriasian stage). Data source: Total of range of species in this database

Plot of occurrence data:

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

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

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

Deflandre, G. & Fert, C. (1954). Observations sur les coccolithophoridés actuels et fossiles en microscopie ordinaire et électronique. Annales de Paléontologie. 40: 115-176. gs

Reinhardt, P. (1965). Neue Familien für fossile Kalkflagellaten (Coccolithophoriden, Coccolithineen). Monatsberichte der Deutschen Akademie der Wissenschaften zu Berlin. 7: 30-40. 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

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


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Eiffellithus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 22-9-2019

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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10406 Go to Archive.is to create a permanent copy of this page - citation notes



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