Nannotax3 - ntax_main - Discoaster extensus Nannotax3 - ntax_main - Discoaster extensus

Discoaster extensus

Variant: Discoaster extensus is regarded here as a variant of Discoaster exilis.
I.e. It is a subjective junior synonym, but some workers many find it useful for some studies (e.g. experienced biostratigraphers working with abundant, well preserved material), but for most purposes differentiating it is not reccomended. Please do use the comments section at the bottom of this page if you wish to discuss this interpretation


Classification: ntax_main -> Discoasterales -> Discoasteraceae -> Discoaster -> D. exilis group -> Discoaster exilis -> Discoaster extensus
Sister taxa: D. caulifloris, D. moorei, D. extensus, D. discissus, D. signus, D. apetalus

Taxonomy:

Citation: Discoaster extensus Hay, in Hay et al. 1967
Taxonomic rank: species

Distinguishing features:
Parent taxon (Discoaster exilis): Small central-area; usually with weak distal and proximal bosses; bifurcations acutely angled in plan-view
This taxon: Ray bifurcations curve proximally

Farinacci & Howe catalog pages: D. extensus *

Search data:
LITHS: nannolith-radiate, star-shaped, CROSS-POLARS: 1ou, V-prominent,
Lith size: 0->0µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within NN11 zone (5.59-8.29Ma, top in Messinian stage). Data source: Browning et al 2017
First occurrence (base): within NN4 zone (14.91-17.95Ma, base in Burdigalian stage). Data source: Browning et al 2017

Plot of occurrence data:

References:

Bramlette, M. N. & Wilcoxon, J. A. (1967a). Discoaster druggi nom. nov. pro Discoaster extensus Bramlette and Wilcoxon, 1967, non Hay, 1967. Tulane Studies in Geology and Paleontology. 5: 220-220. gs

Browning, E., Bergen, J. A., Blair, S. A., Boesiger, T. M. & de Kaenel, E. (2017). Late Miocene to Late Pliocene taxonomy and stratigraphy of the genus Discoaster in the circum North Atlantic Basin: Gulf of Mexico and ODP Leg 154. Journal of Nannoplankton Research. 37(2-3): 189-214. gs

Hay, W. W., Mohler, H. P., Roth, P. H., Schmidt, R. R. & Boudreaux, J. E. (1967). Calcareous nannoplankton zonation of the Cenozoic of the Gulf Coast and Caribbean-Antillean area, and transoceanic correlation. Transactions of the Gulf-Coast Association of Geological Societies. 17: 428-480. gs O


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Discoaster extensus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 16-11-2025

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1602 Go to Archive.is to create a permanent copy of this page - citation notes



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