Nannotax3 - ntax_cenozoic - D. deflandrei group Nannotax3 - ntax_cenozoic - D. deflandrei group

D. deflandrei group


Classification: ntax_cenozoic -> 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 (time control age-window is: 0-800Ma)Granddaughter taxa
Discoaster deflandrei
6-rayed discoaster with a well developed central area; rays ending in strong short wide bifurcations.
Discoaster calculosus
Discoaster salomonii
Discoaster emblematicus
Discoaster durioi
Discoaster saundersi
Discoaster nephados
Discoaster leroyi

Discoaster kugleri
Central-area wide and flat. Free rays short, with notched ends rather than true bifurcations; often thicker than the central area.
Discoaster hexapleuros
Discoaster cuspidatus

Discoaster druggii
Like D. deflandrei but larger, >15µm, and without distinct bifurcations
Discoaster shumnykii

Taxonomy:

Citation: Discoaster deflandrei group
taxonomic rank: species group
Taxonomic 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:
Parent taxon (Discoaster): Radiate nannoliths with each ray formed of a discrete crystal-unit, with the c-axes perpendicular to the nannolith surface.
This taxon: Complanate 6-rayed discoasters with robust bifurcations and smple central-areas

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

Search data:
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): at top of NN8 zone (100% up, 10.6Ma, in Tortonian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within NP10 zone (54.17-55.86Ma, base in Ypresian stage). Data source: Total of ranges 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 O


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D. deflandrei group compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 17-7-2024

Taxon Search:
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Short stable page link: https://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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