Cylindralithus nudus


Classification: Mesozoic -> Watznaueriales -> Watznaueriaceae -> Ansulasphaera -> Cylindralithus nudus
Sister taxa: A. bownii, A. covingtonii, A. helvetica, C. nudus, A. sp.,

Distinguishing features: Elliptical; central area narrow and open.


Taxonomy:

Citation: Cylindralithus nudus Bukry, 1969
Rank: Species
Notes & discussion: Should be reclassified in Ansulasphaera (see morphology remarks)

Farinacci & Howe catalog pages: C. nudus *

Distinguishing features: Elliptical; central area narrow and open.


Morphology remarks: As Bown & Young (1997) suggested, this species appears to be a member of the Watznaueriaceae, with elevated shields. The V-unit tube-core cycle can be seen in good SEMs, and in the TEMs of Bukry (1969). Most other species of Cylindralithus, however, do not show this structure and almost certainly are Stephanolithiaceae, as traditionally classified (e.g. Perch-Nielsen 1985, Burnett 1998). Based on this structure the species should probably be recombined into Ansulasphaera. [my interpretation - JRY 2015]

Search data:
TagsLITHS: placolith, elliptical, cylindrical, hollow, CA: vacant, CROSS-POLARS: rim-unicyclic, V-prominent,
MetricsLith size: 4->6µm;
Data source notes: illustrated specimens
The morphological data given here can be used on the advanced search page. See also these notes

See also: Cylindralithus ;Perchnielsenella ;

Geological Range:
Last occurrence (top): at top of Maastrichtian Stage (100% up, 66Ma, in Maastrichtian stage). Data source: Lees & Bown 2005 - consistently present to end Cret
First occurrence (base): in lower part of BC23 zone (20% up, 111.5Ma, in Albian stage). Data source: Bown et al. 1998, fig. 5.4

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 V O

Bown, P. R. & Young, J. R. (1997). Mesozoic calcareous nannoplankton classification. Journal of Nannoplankton Research. 19(1): 21-36. gs V O

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 V O

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

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

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

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

Lambert, B. (1993). Nannofossiles calcaires de l'Albien supérieur et du Vraconnien du Cameroun méridional (Deuxième Partie). Cahiers de Micropaléontologie. 8(2): 183-225. 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 V O

Perch-Nielsen, K. (1985b). Mesozoic calcareous nannofossils. In, Bolli, H. M. , Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge 329-426. gs

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


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Cylindralithus nudus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 30-9-2020

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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10359 Go to Archive.is to create a permanent copy of this page - citation notes



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