Discoaster williamsii
Classification: ntax_cenozoic -> Discoasterales -> Discoasteraceae -> Discoaster -> D. nodifer group -> Discoaster williamsii
Sister taxa: D. cruciformis, D. colletii, D. gemmifer, D. mediosus, D. binodosus, D. nodifer, D. distinctus, D. septemradiatus, D. tanii, D. tani ornatus, D. istanbulensis, D. martinii, D. williamsii, D. backmanii, D. okadai
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Taxonomy:
Citation: Discoaster williamsii Bown & Dunkley Jones, 2012Rank: SpeciesTaxonomic discussion: Distinguished from Discoaster nodifer by the broad central area and large central area bosses.
Distinguishing features: 5-6 rayed discoaster with broad central area that is distinctly elevated on both faces. The rays are narrow and free for around half their length. Paired lateral nodes just before the ray tips are present in some specimens
Farinacci & Howe catalog pages: D. williamsii *
Size: Holotype length 14.0 microns
Search data:
Tags | LITHS: nannolith-radiate, star-shaped, CA: process, CROSS-POLARS: 1ou, V-prominent, |
Metrics | Lith size: 10->18µm; Segments: 5->6; Data source notes: size from illustrated specs |
The morphological data given here can be used on the advanced search page. See also these notes
Geological Range:
Last occurrence (top): within NP19-20 zone (34.44-36.97Ma, top in Priabonian stage). Data source: Bown & Dunkley Jones, 2012
First occurrence (base): within NP15b subzone (44.12-45.49Ma, base in Lutetian stage). Data source: Bown & Dunkley Jones, 2012
Plot of occurrence data:
- Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
- Triangles indicate an event for which a precise placement has been suggested
- (NB There is no histogram as there are no occurrence records for the taxon in the Neptune database) Parent: D. nodifer group
References:
Bown, P. R. & Dunkley Jones, T. (2012). Calcareous nannofossils from the Paleogene equatorial Pacific (IODP Expedition 320 Sites U1331-1334). Journal of Nannoplankton Research. 32(2): 3-51. gs V O