Nannotax3 - ntax_cenozoic - Discoaster bergenii

Discoaster bergenii


Classification: ntax_cenozoic -> Discoasterales -> Discoasteraceae -> Discoaster -> D. quinqueramus group -> Discoaster bergenii
Sister taxa: D. quinqueramus, D. berggrenii, D. consutus, D. bergenii

Sub-taxa & variants (time control age-window is: 0-800Ma)
Discoaster compactus
stem-ridges extend to edge of central area - very short rays
Discoaster vinsonii
stem-ridges extend to edge of central area - very short rays
Discoaster abrachiatus
no free rays

Taxonomy:

Citation: Discoaster bergenii Knuttel, Russell and Firth, 1989
Rank: Species
Synonyms:
Taxonomic discussion: In the taxonomy of de Kaenel et al. (2017) D. bergenii is spearatd from the other speciesi listed here as variants by having stem ridges which extend beyond the central area. 

Distinguishing features:
Parent taxon (D. quinqueramus group): Symmetric typically 5-rayed, late Miocene discoasters; rays curved proximally, without bifurcations; well-developed distal star and usually proximal boss
This taxon: very short free rays

Farinacci & Howe catalog pages: D. bergenii + * , D. pentaperforatus *


Morphology:

Like D. quinqueramus but central-area very wide (>2x free ray length).

Size:

Search data:
TagsLITHS: nannolith-radiate, pentagonal, star-shaped, CA: process, CROSS-POLARS: 1ou, V-prominent,
MetricsLith size: 5->10µm; Segments: 5->5;
Data source notes: size from OD & illustrated specs
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: D. bergenii, D. bergrennii and D. quinqueramus apparently form an anagenetic lineage, with central area size deceasing and free ray length increasing. Distinguishing them is useful for determining position within the early part of zone NN11.
Last occurrence (top): in mid part of NN11 zone (50% up, 6.9Ma, in Messinian stage). Data source: Blair et al 2017
First occurrence (base): at base of NN11 zone (0% up, 8.3Ma, in Tortonian stage). Data source: Blair et al 2017

Plot of occurrence data:

References:

Bergen, J. A. (1984). Calcareous nannoplankton from Deep Sea Drilling Project Leg 78A: evidence for imbricate underthrusting at the Lesser Antillian active margin. Initial Reports of the Deep Sea Drilling Project. 78A: 411-445. gs V O

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 O

Knuttel, S., Russell, M. D. & Firth, J. V. (1989). Neogene calcareous nannofossils from Leg 105: Implications for Pleistocene paleoceanographic trends. Proceedings of the Ocean Drilling Program, Scientific Results. 105: 245-262. gs V O

Singh, O. P & Jafar, S. A. (1995). Late Miocene discoasters from Sawai Bay Formation, Neill Island, Andaman Sea, India. The Palaeobotanist. 44: 189-206. gs V O

Theodoridis, S. (1984). Calcareous nannofossil biostratigraphy of the Miocene and revision of the helicoliths and discoasters. Utrecht Micropaleontological Bulletin. 32: 1-271. gs O

Wei, W. (2003). Upper Miocene nannofossil bistratigraphy and taxonomy of Exxon core CH30-43-2 from the Gulf of Mexico. Journal of Nannoplankton Research. 25(1): 17-23. gs V O

Young, J. R. (1998). Neogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 225-265. gs V O


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Discoaster bergenii compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 26-6-2022

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=451 Go to Archive.is to create a permanent copy of this page - citation notes



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Mike Styzen (Noble Energy, US)
Discoaster quinqueramus/berggrenii plexus: I posted a document with some sketches from the original Gulf Coast Taxonomic Equivalency Project of this group in the forum.
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