D. exilis group


Classification: Coccolithophores -> Discoasterales -> Discoasteraceae -> Discoaster -> D. exilis 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) Granddaughter taxa
D. exilis and variants
Small central-area; usually with weak distal and proximal bosses; bifurcations acutely angled in plan-view

large stellate stem and wide bifurcations

Asymetric 5-rayed discoaster with bifurcations.

Ray bifurcations curve proximally

Wide, tapering rays with notched tips.

D. bollii
Similar to D. exilis but with large distal boss, small proximal boss, and wide central-area, and usually smaller (<10µm).

D. petaliformis & similar
Similar to D. exilis but with very large mushroom-shaped distal boss and distinct proximal boss. Central-area narrow.

Similar to D. petaliformis but with longer bifurcations, and weaker boss. 

Like D. petaliformis but without the central boss

Taxonomy:

Citation: Discoaster exilis group de Kaenel et al. 2017
Rank: species group

Farinacci & Howe catalog pages: Discoaster exilis 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 mid part of Tortonian Stage (48% up, 9.5Ma, in Pannonian stage). Data source: Total of range of species in this database
First occurrence (base): in upper part of Burdigalian Stage (56% up, 17.9Ma, in Burdigalian 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. exilis group compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 25-8-2019

Taxon Search:
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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=1547 Go to Archive.is to create a permanent copy of this page - citation notes



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