Pentaster lisbonensis

Classification: ntax_cenozoic -> Braarudosphaerales -> Braarudosphaeraceae -> Pentaster -> Pentaster lisbonensis
Sister taxa: P. lisbonensis


Citation: Pentaster lisbonensis Bybell & Gartner 1972
Rank: Species
Taxonomic discussion: The original description does not provide conclusive evidence that this is a pentalith, and the SEM images in Bybell (1975) suggest it may even be a sphenolith, so it would be useful to have gypsum plate observations of the crystallographic orientation of the rays. [editor's comment - JRY 2019]

Distinguishing features: 5 rayed nannolith with complex struture

Farinacci & Howe catalog pages: P. lisbonensis *

Morphology: Described as having "the basic structure of a dodecahedron of pentagons with five long rays projecting from the equator".

See also: Micrantholithus mirabilis - possible overgrown variant/senior synonym;

Search data:
TagsLITHS: nannolith-radiate, pentagonal, star-shaped, CA: process, CROSS-POLARS: T-prominent,
MetricsLith size: 12->15µm; Segments: 5->5;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: No records in Neptune database but recorded as stratigraphically useful in nearshore deposits of both NE USA (Eg. Edwards et al. 2000) and NW Europe (e.g. Steurbaut 1988)
Last occurrence (top): within Middle Eocene Sub-Epoch (37.75-47.84Ma, top in Bartonian stage). Data source: Bybell & Gartner 1972
First occurrence (base): within NP15 zone (42.87-46.29Ma, base in Lutetian stage). Data source: Edwards et al. 2000

Plot of occurrence data:


Bybell, L. M. & Gartner, S. (1972). Provincialism among mid-Eocene calcareous nannofossils. Micropaleontology. 18(319-336): -. gs

Bybell, L. (1975). Middle Eocene calcareous nannofossils at Little Stave Creek, Alabama. Tulane Studies in Geology and Paleontology. 11(4): 177-247. gs V O

Edwards, L. et al. (2000). Supplement to the preliminary stratigraphic database for subsurface sediments of Dorchester county, South Carolina ( U.S. Geological Survey Open-file Report. 1-2. gs

Steurbaut, E. (1988). New Early and Middle Eocene calcareous nannoplankton events and correlations in middle to high latitudes of the northern hemisphere. Newsletters on Stratigraphy. 18: 99-115. gs


Pentaster lisbonensis compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 14-4-2021

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Short stable page link: Go to to create a permanent copy of this page - citation notes

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