Nannotax3 - ntax_mesozoic - Micula premolisilvae Nannotax3 - ntax_mesozoic - Micula premolisilvae

Micula premolisilvae


Classification: ntax_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:
Parent taxon (Micula): Typically cubiform nannoliths usually formed from two superimposed and complexly-intergrown cycles of four pyramidal/blocky elements each
This taxon: 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
taxonomic rank: Species

Farinacci & Howe catalog pages: M. premolisilvae *

Distinguishing features:
Parent taxon (Micula): Typically cubiform nannoliths usually formed from two superimposed and complexly-intergrown cycles of four pyramidal/blocky elements each
This taxon: A near-square to cruciform, flat Micula, composed of a single cycle of four elements joined along distinct straight, or gently curving, sutures.


Morphology:

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.

Search data:
LITHS: nannolith-radiate, quadrate, CA: closed,
Lith size: 5->8µm; Segments: 4->4;
Data source notes: original description & illustrated specimens
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within Maastrichtian Stage (66.04-72.17Ma, top in Maastrichtian stage). Data source: Lees & Bown 2005
First occurrence (base): within Late Campanian Substage (72.17-76.20Ma, base in Campanian stage). Data source: Lees & Bown 2005

Plot of occurrence data:

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: 20-9-2024

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Short stable page link: https://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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