arrayname: original 
Nannotax3 - ntax_mesozoic - Polycostella parvistellatus Nannotax3 - ntax_mesozoic - Polycostella parvistellatus

Polycostella parvistellatus


Classification: ntax_mesozoic -> Braarudosphaerales -> Transitional genera -> Polycostella -> Polycostella parvistellatus
Sister taxa: P. senaria, P. beckmannii, P. parvistellatus, P. sp.

Distinguishing features:
Parent taxon (Polycostella): Globular and stellate nannoliths formed of 5-8 segments of stacked elements. Nannoconus-like in side view.  
This taxon: Small (<6 µm) form formed of 5 segments


Taxonomy:

Citation: Polycostella parvistellatus (Varol 1991) Varol & Bowman 2019
Taxonomic rank: species
Basionym: Micrantholithus? parvistellatus Varol 1991
Taxonomic discussion: Varol (1991) suggested that the species shows similarity to Polycostella.  
The combination P. parvistellatus  was proposed by Bergen et al. 2014, but, as noted by Varol & Bowman (2019), the combination was not validly proposed (ICN Art 45.1), since the Varol 1991 reference was missing from their bibliography.

Farinacci & Howe catalog pages: M. parvistellatus *

Distinguishing features:
Parent taxon (Polycostella): Globular and stellate nannoliths formed of 5-8 segments of stacked elements. Nannoconus-like in side view.  
This taxon: Small (<6 µm) form formed of 5 segments


Morphology:

Small (< 6.0 μm) nannoconid having five longitudinal ridges. The wall cycles are thin and low- angled, and the axial canal is very narrow. It is stellate in plan view and has sutures between the segments, which meet at the periphery of the vertices of the nannolith. It is strongly birefringent in plan view, but weakly birefringent or non-birefringent in side view.

Search data:
LITHS: nannolith-radiate, pentagonal, star-shaped, cylindrical, CA: closed, CROSS-POLARS: T-prominent,
Lith size: 4->6µm; Segments: 5->5;
Data source notes: original description & illustrated specimens
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within Early Berriasian Substage (141.40-143.10Ma, top in Berriasian stage). Data source: Varol & Bowman 2019
First occurrence (base): within Late Tithonian Substage (143.10-145.00Ma, base in Tithonian stage). Data source: Varol & Bowman 2019

Plot of occurrence data:

References:

Bergen, J. A., Boesiger, T. M. & Pospichal, J. J. (2014). Low-latitude Oxfordian to Early Berriasian nannofossil biostratigraphy and its application to the subsurface of Eastern Texas. In, Hammes, U. & Gale, J. (eds) Geology of the Haynesville Gas Shale in East Texas and West Louisiana, U.S.A. American Association of Petroleum Geologists, Memoirs . 105: 69-102. gs

Varol, O. & Bowman, A. R. (2019). Taxonomic revision of selected Late Jurassic (Tithonian) calcareous nannofossils and the application of mobile mounting. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 291: 65-87. gs

Varol, O. (1991). New Cretaceous and Tertiary Calcareous Nannofossils. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 182: 211-237. gs


nannotaxlogo400px

Polycostella parvistellatus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 21-4-2025

Taxon Search:
Advanced Search

Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10660 Go to Archive.is to create a permanent copy of this page - citation notes
nannotaxlogo400px

Nannotax is being sponsored through 2024 by Woodside Energy and Shell USA


Add Comment

* Required information
Captcha Image

Comments

No comments yet. Be the first!