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.


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

Farinacci & Howe catalog pages: Cylindralithus 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]

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:

  • Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
  • Note to users in China - the diagram may not plot unless you use a VPN since I use google services on the website. If this is a problem please contact me 谢谢.
  • Taxon plotted: Cylindralithus nudus, synonyms included - Cylindralithus nudus; Cylindralithus nudus (subcircular); testttspace-time plot :: Samples map :: Parent: Ansulasphaera


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

    Bown, P.R.; Rutledge, D.C.; Crux, J.A. & Gallagher, L.T., (1998). Early Cretaceous. In: Bown, P.R. (Editor), Calcareous nannofossil biostratigraphy. British Micropalaeontological Society Publication Series. Chapman & Hall, pp. 86-131.GS

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

    Burnett, J.A., (1998). Upper Cretaceous. In: Bown, P.R. (Editor), Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publications Series. Chapman & Hall, London, pp. 132-199.GS

    Perch-Nielsen, K., (1985). Mesozoic calcareous nannofossils. In: Bolli, H.M., Saunders, J.B. and Perch-Nielsen, K. (Editors), Plankton Stratigraphy. Cambridge University Press, Cambridge, pp. 329-426.GS


    Cylindralithus nudus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 24-3-2019

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