Nannotax3 - ntax_cenozoic - Discoaster araneus

Discoaster araneus

Classification: ntax_cenozoic -> Discoasterales -> Discoasteraceae -> Discoaster -> D. araneus group -> Discoaster araneus
Sister taxa: D. anartios, D. salisburgensis var. villosus, D. araneus, D. acutus


Citation: Discoaster araneus Bukry, 1971
Rank: Species
Basionym: Discoaster araneus Bukry, 1971
Taxonomic discussion: PETM excursion taxon. Bralower & Self-Trail (2016) argue that this is better regarded as a sub-species of D. salisburgensis.

Distinguishing features:
Parent taxon (D. araneus group): Irregular "malformed" discoasters characteristic of the PETM excursion
This taxon: 7-9 rays. Large to very large, typically asymmetric discoaster with a prominent boss on one side and 7-9 tapering rays that have variable curvature and free length (1/3 to 2/3 of total ray length).

Farinacci & Howe catalog pages: D. araneus * , D. aegyptiacus duwiensis *



See also: Discoaster salisburgensis - the non-malformed species this form is derived from, according to Bralower & Self-Trail (2016);

Search data:
LITHS: nannolith-radiate, asymmetric, star-shaped, CA: process, CROSS-POLARS: 1ou, V-prominent,
Lith size: 12->25µm; Segments: 7->13;
Data source notes: size from OD and specs illustrated in Bralower & Self-Trail 2016
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within NP10 zone (54.17-55.86Ma, top in Ypresian stage). Data source: PRB entry to Nannotax
First occurrence (base): within NP9 zone (55.86-57.21Ma, base in Thanetian stage). Data source: PRB entry to Nannotax

Plot of occurrence data:


Bralower, T. J. & Self-Trail, J. (2016). Nannoplankton malformation during the Paleocene-Eocene Thermal Maximum and its paleoecological and paleoceangraphic significance. Paleoceanography. 31: 1-17. gs

Bukry, D. (1971a). Discoaster evolutionary trends. Micropaleontology. 17: 43-52. gs V O

El-Dawoody, A. S. (1988). New calcareous nannoplankton species from the Paleocene rocks in souhern Egypt. Bulletin of the Faculty of Science, Cairo University. 56: 549-563. gs

Self-Trail, J. (2011). Paleogene Calcareous Nannofossils of the South Dover Bridge core, Southern Maryland (USA). Journal of Nannoplankton Research. 32(1): 1-28. gs V O

Self-Trail, J. M., Powars, D. S., Watkins, D. K. & Wandless, G. A. (2012). Calcareous nannofossil assemblage changes across the Paleocene–Eocene Thermal Maximum: Evidence from a shelf setting. Marine Micropaleontology. 92–93: 61-80. gs

Steurbaut, E. (1998). High–resolution holostratigraphy of Middle Paleocene to Early Eocene strata in Belgium and adjacent areas. Palaeontographica Abteilung A Palaeozoologie Stratigraphie. 247: 91-256. gs


Discoaster araneus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 26-9-2022

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