Tubodiscus


Classification: Mesozoic -> Podorhabdales -> Tubodiscaceae -> Tubodiscus
Sister taxa: Manivitella, Tubodiscus,

Distinguishing features: Tubodiscids with high and birefringent proximal collar cycle and wide central-area. Rim image is clearly bicyclic in XPL.


Daughter taxa: (blue => in age window 0-800Ma)
Medium sized (5-7 µm) with narrow shields / wide central area. In xpl the inner rim cycle is usually slightly narrower than the outer rim cycle
Medium to large (5-10 µm), typically broadly elliptical; the central area is broad (usually greater than the width of the rim). Inner and outer rim cycles of similar width.
Medium sized (5-7 µm) with relatively broad shields/relatively narrow central area; in xpl inner rim cycle significantly narrower than the outer rim cycle.
Large (8-16 µm) with wide central area. Inner and outer rim cycles of similar width.
Large (8-16 µm) Tubodiscus with broad, high collar cycle that is highly birefringent (yellow-orange) in XPL; often seen in side view.
Specimens not identified to species level

Taxonomy:

Citation: Tubodiscus Thierstein, 1973
Rank: Genus
Type species: Tubodiscus verenae Thierstein, 1973.

Farinacci & Howe catalog pages: Tubodiscus *

Distinguishing features: Tubodiscids with high and birefringent proximal collar cycle and wide central-area. Rim image is clearly bicyclic in XPL.

Search data:
TagsLITHS: placolith, elliptical, CA: vacant, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent,
MetricsLith size: 5->16µm;
Data source notes: size range of included species
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): at top of Albian Stage (100% up, 100.5Ma, in Albian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Berriasian Stage (0% up, 145Ma, in Berriasian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

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

Thierstein, H. R. (1973). Lower cretaceous calcareous nannoplankton biostratigraphy. Abhandlungen der Geologischen Bundesanstalt. 29: 3-52. gs V O


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Tubodiscus 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=11272 Go to Archive.is to create a permanent copy of this page - citation notes



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