Nannotax3 - ntax_mesozoic - Eiffellithus paragogus

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: 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.

Citation: Eiffellithus paragogus Gartner, in Robaszynski et al 1993.

Basionym: Bownia glabra Jeremiah, 1996

Synonyms:

Coccolithus matalosus Stover 1966, partim, p. 137, pl. 2, fig. 1a-c; pl. 8, fig. 10; non, pl. 2, fig 2a-b.
Bownia glabra Jeremiah, 1996
Staurolithites glabra (Jeremiah 1996) Burnett 1997
Staurolithites glaber (Jeremiah 1996) Burnett 1998

Taxonomic discussion: This form was confused with Broinsonia matalosa for an extended period then recognised as a discrete form by both Gartner (1993) who described it as E. paragogus, and independently by Jeremiah (1996) who described it as Bownia glabra. The specific name glabra/glaber has been widely used but is clearly a junior synonym of paragogus. The generic assignment is, however, less clear. See Watkins & Bergen (2003) for extended discussion, or Bergen (1998).

Distinguished from Broinsonia by its smooth margin and outer wall cycle (which flares quite markedly in the LM). It is distinguished from Eiffellithus monechiae and Eiffellithus eximius by the relatively simple appearance of its cross in XPL.

Most likely ancestor: Staurolithites angustus - at confidence level 3 (out of 5). Data source: Watkins & Bergen 2003.

Geological Range:
Last occurrence (top): in mid part of UC1c subzone (50% up, 99.1Ma, in Cenomanian stage). Data source: Burnett 1998, fig 6.2
First occurrence (base): within Aptian Stage (113.20-121.40Ma, base in Aptian stage). Data source: Burnett 1998

References:

Bergen, J. A. (1998). Calcareous nannofossils from the lower Aptian historical stratotype at Cassis-La Bedoule (SE France). Géologie Méditerranéene. 25(3-4): 227-255. 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

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

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

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

Jeremiah, J. (1996). A proposed Albian to Lower Cenomanian nannofossil biozonation for England and the North Sea Basin. Journal of Micropalaeontology. 15(97-129): -. gs

Kanungo, S., Bown, P. R. & Gale, A. S. (2020). Cretaceous (Albian-Turonian) calcareous nannofossil biostratigraphy of the onshore Cauvery Basin, southeastern India. Cretaceous Research. 118 [2021]: 1-22. gs

Kennedy, W. J. et al. (2000). Integrated stratigraphy across the Aptian-Albian boundary in the Marnes Bleues, at the Col de Pre _-Guittard, Arnayon (Drome), and at Tartonne (Alpes-de-Haute-Provence), France: a candidate Global Boundary Stratotype Section and Boundary Point for the base of the Albian Stage. Cretaceous Research. 21: 591-720. gs

Robaszynski, F. et al. (1993). Le Cénomanien de la région de Kalaat Senan (Tunisie centrale): Litho-biostratigraphie et interprétation séquentielle. Revue de Paléobiologie. 12(2): 351-505. gs

Roth, P. H. & Thierstein, H. R. (1972). Calcareous nannoplankton: Leg 14 of the Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project. 12: 546-559. gs O

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

Eiffellithus paragogus

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