Variant: Discoaster gemmulatus is regarded here as a variant of Discoaster bellus.
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
Taxonomy:
Distinguishing features:
Parent taxon (Discoaster bellus): Symmetric 5-rayed species with simple ray tips
This taxon: Like D. bellus but with weak central knob
Farinacci & Howe catalog pages: D. gemmulatus *
Phylogenetic relations
LITHS: nannolith-radiate, star-shaped, CROSS-POLARS: 1ou, V-prominent, |
Lith size: 0->0µm; |
Geological Range:
Notes: Range similar to D. bellus.
Last occurrence (top): within NN11 zone (5.59-8.29Ma, top in Messinian stage). Data source: Blair et al 2017
First occurrence (base): within NN8 zone (10.55-10.89Ma, base in Tortonian stage). Data source: Blair et al 2017
Plot of occurrence data:
Blair, S. A., Bergen, J. A., de Kaenel, E., Browning, E. & Boesiger, T. M. (2017). Upper Miocene-Lower Pliocene taxonomy and stratigraphy in the circum North Atlantic Basin: radiation and extinction of Amauroliths, Ceratoliths and the D. quinqueramus lineage. Journal of Nannoplankton Research. 37(2-3): 113-144. gs OReferences:
Discoaster gemmulatus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 11-9-2024
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1593 Go to Archive.is to create a permanent copy of this page - citation notes |
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