Daughter taxa (time control age-window is: 0-800Ma)![]() | Granddaughter taxa | ||||
![]() | ![]() | ![]() | Discoaster pentaradiatus Ray tips with acute bifurcations; strongly concavo-convex; birefringent | ||
![]() | Discoaster prepentaradiatus Symmetric with bifurcations; rays planar and all show similar birefringence. | ||||
![]() | ![]() | Discoaster hamatus 5-rayed; ray tips with clockwise deflected (in distal view) proximal extensions. | |||
![]() | Discoaster bellus Symmetric 5-rayed species with simple ray tips |
Taxonomy:
Distinguishing features: Symmetric 5-rayed, late Neogene, discoasters without large proximal boss
Farinacci & Howe catalog pages:
Morphology: This is an informal grouping for symmetric 5-rayed discoasters. These species probably do not form a clade but are a characteristic component of Late Miocene and Pliocene assemblages, including several important marker species.
Tags | LITHS: |
Metrics | Lith size: 7->20µm; |
Geological Range:
Notes: This group is confined the Late Miocene and Pliocene and the absence of the group is a useful indication of earlier age. Most individual species are also stratigraphically valuable so this is one of the most stratigraphically vauable groups of nannofossils in the entire Cenozoic.
Last occurrence (top): in lower part of Gelasian Stage (26% up, 2.4Ma, in Gelasian stage). Data source: Total of range of species in this database
First occurrence (base): in lower part of Tortonian Stage (17% up, 10.9Ma, in Tortonian stage). Data source: Total of range of species in this database
Plot of occurrence data:
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D. pentaradiatus group compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 2-3-2021
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=423 Go to Archive.is to create a permanent copy of this page - citation notes |