Micula premolisilvae


Classification: Mesozoic -> Braarudosphaerales -> Polycyclolithaceae -> Micula -> Micula premolisilvae
Sister taxa: M. staurophora, M. adumbrata, M. concava, M. cubiformis, M. swastica, M. murus, M. prinsii, M. clypeata, M. praemurus, M. premolisilvae, M. sp.,

Distinguishing features: A near-square to cruciform, flat Micula, composed of a single cycle of four elements joined along distinct straight, or gently curving, sutures.


Taxonomy:

Citation: Micula premolisilvae Lees & Bown, 2005
Rank: Species

Farinacci & Howe catalog pages: Micula premolisilvae *

Distinguishing features: A near-square to cruciform, flat Micula, composed of a single cycle of four elements joined along distinct straight, or gently curving, sutures.


Morphology remarks: Similar in morphology to M. praemurus but the outline is square or cruciform rather than circular. The orientation of the sutures is variable ranging from axial to near-diagonal. Much flatter than most other Miculas but most similar to M. praemurus and M. clypeata, to which it may be more closely related. The entire nannolith goes into extinction when the sides of the square are rotated to 45° from the polarising directions.

Size: Length/width 5.0-6.5µm.

Geological Range:
Last occurrence (top): within Maastrichtian Stage (66.04-72.05Ma, top in Maastrichtian stage). Data source: Lees & Bown 2005
First occurrence (base): within Late Campanian Substage (72.05-76.38Ma, base in Campanian stage). Data source: Lees & Bown 2005

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: Micula premolisilvae, synonyms included - Micula premolisilvae;
  • space-time plot :: Samples map :: Parent: Micula

    References:

    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

    Perez-Rodriguez, I., Lees, J. A., Larasoaña, J. C., Arz, J. A. & Arenillas, I. (2012). Planktonic foraminiferal and calcareous nannofossil biostratigraphy and magnetostratigraphy of the uppermost Campanian and Maastrichtian at Zumaia, northern Spain. Cretaceous Research. 37: 100-126. gs


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    Micula premolisilvae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 12-11-2019

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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10680 Go to Archive.is to create a permanent copy of this page - citation notes



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