D. deflandrei group


Classification: Coccolithophores -> Discoasterales -> Discoasteraceae -> Discoaster -> D. deflandrei group
Sister taxa: D. brouweri group, D. pentaradiatus group, D. quinqueramus group, D. variabilis group, D. exilis group, D. musicus group, D. deflandrei group, D. nodifer group, D. lodoensis group, D. multiradiatus group, D. araneus group, D. sp.,

Daughter taxa: (blue => in age window 0-800Ma)
D. deflandrei and variants
6-rayed discoaster with a well developed central area; rays ending in strong short wide bifurcations.
broad central area, large (>15 µm) with "broad & shallow inter-ray areas
broad central area
broad central-area, ornate & broadly rounded bifurcation
ornate central-area & angular bifurcation
ornate central-area & angular bifurcation
short flaring rays & very broad bifurcation
5-rayed variant of D. deflandrei
D. kugleri and variants
Central-area wide and flat. Free rays short, with notched ends rather than true bifurcations; often thicker than the central area.
Like D. kugleri but with parallel-sided rays and hexagonal central area periphery.
Like D. kugleri but with longer, tapering rays.
D. druggii and variants
Like D. deflandrei but larger, >15µm, and without distinct bifurcations

Taxonomy:

Citation: Discoaster deflandrei group
Rank: species group
Notes & discussion: This is the dominant discoaster group from the Oligocene to the Middle Miocene. They are variable in shape of the terminations, central area width and whether a boss is present in the centre, but these features are intergradational and frequently obscured by diagenesis. Many workers identify the vast majority of specimens as D. deflandrei. Additional important and widely used species are D. druggii and D. kugleri.

Distinguishing features: Complanate 6-rayed discoasters with robust bifurcations and smple central-areas

Farinacci & Howe catalog pages: Discoaster deflandrei group [no catalog entry yet]

Search data:
Tags
MetricsLith size: 0->0µm;
Sources:
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): in lower part of Tortonian Stage (17% up, 10.9Ma, in Pannonian stage). Data source: Total of range of species in this database
First occurrence (base): in upper part of Ypresian Stage (67% up, 50.5Ma, in Ypresian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

de Kaenel, E., Bergen, J. A., Browning, E., Blair, S. A. & Boesiger, T. M. (2017). Uppermost Oligocene to Middle Miocene Discoaster and Catinaster taxonomy and stratigraphy in the circum North Atlantic Basin: Gulf of Mexico and ODP Leg 154. Journal of Nannoplankton Research. 37(2-3): 215-244. gs


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D. deflandrei group compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 20-8-2019

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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=1543 Go to Archive.is to create a permanent copy of this page - citation notes



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