Nannotax3 - ntax_mesozoic - Nannoconus pseudoseptentrionalis <title>Nannotax3 - ntax_mesozoic - Nannoconus pseudoseptentrionalis

Nannoconus pseudoseptentrionalis


Classification: ntax_mesozoic -> Braarudosphaerales -> Nannoconaceae -> Nannoconus -> Nannoconus - atypical -> Nannoconus pseudoseptentrionalis
Sister taxa: N. funiculus, N. ligius, N. magnadiscus, N. nicholasii, N. pseudoseptentrionalis, N. sabinae

Distinguishing features:
Parent taxon (Nannoconus - atypical): Atypical nannoconids, not fitting in any of the main groups
This taxon: Short nannoconid with narrow canal and ragged outline in plan view. Seen mainly in plan view.


Taxonomy:

Citation: Nannoconus pseudoseptentrionalis Rutledge & Bown, 1996
Rank: Species

Farinacci & Howe catalog pages: N. pseudoseptentrionalis *

Distinguishing features:
Parent taxon (Nannoconus - atypical): Atypical nannoconids, not fitting in any of the main groups
This taxon: Short nannoconid with narrow canal and ragged outline in plan view. Seen mainly in plan view.


Morphology:

N. pseudoseptentrionalis is differentiated from other similar nannoconids by its irregular, ragged margin; this renders it similar to T. septentrionalis in XPL. These optically similar species are readily differentiated in PC (in which T. septentrionalis displays regularly-spaced wall elements), and in side view (T. septentrionalis is commonly encountered in highly distinctive side view). In end view, N. pseudoseptentrionalis lacks the weakly birefringent flanges often (but not always) seen on T. septentrionalis.

Size:
4.5-7µm in diameter.


Ecology & Biogeography


Biology & life-cycles

Phylogenetic relations

Search data:
LITHS: nannolith-radiate, circular, cylindrical, hollow, CA: vacant, CROSS-POLARS: T-prominent,
Lith size: 4.5->7µm;
Data source notes: original description
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within Early Barremian Substage (129.41-130.77Ma, top in Barremian stage). Data source: Bown et al. 1998
First occurrence (base): within Early Barremian Substage (129.41-130.77Ma, base in Barremian stage). Data source: Bown et al. 1998

Plot of occurrence data:

References:

Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Lower Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 86-131. gs O

Jeremiah, J. (2001). A Lower Cretaceous nannofossil zonation for the North Sea Basin. Journal of Micropalaeontology. 20(1): 45-80. gs V O

Rutledge, D. & Bown, P. R. (1996). New names for old: taxonomic clarification of some Early Cretaceous nannofossil marker-species. Journal of Nannoplankton Research. 18(2): 53-59. gs V O


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Nannoconus pseudoseptentrionalis compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 29-1-2023

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10766 Go to Archive.is to create a permanent copy of this page - citation notes



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