Nannotax3 - ntax_mesozoic - Perchnielsenella

Perchnielsenella


Classification: ntax_mesozoic -> Watznaueriales -> Watznaueriaceae -> Perchnielsenella
Sister taxa: Bussonius, Cyclagelosphaera, Diazomatolithus, Lotharingius, Watznaueria ⟩⟨ Ansulasphaera, Bibreviconus, Perchnielsenella

Distinguishing features:
Parent taxon (Watznaueriaceae): Placoliths or modified placoliths with R-unit well developed, forming proximal and distal shield elements with opposite senses of imbrication; the V-unit typically forms a narrow distal cycle near the inner edge of the shield. Central-area structures are typically disjunct. Birefringent LM image, in which the V-unit cycle appears only as a thin, dark line.
This taxon: Medium to large, barrel-shaped coccoliths that are highly-birefringent and seen in both side and plan view.


Daughter taxa (time control age-window is: 0-800Ma)
Perchnielsenella stradneri
Medium to large, barrel-shaped coccoliths that are highly-birefringent and seen in both side and plan view. Narrow central area.
Perchnielsenella sp.
Specimens not identified to species level

Taxonomy:

Citation: Perchnielsenella Watkins in Watkins & Bowdler, 1984
Rank: Genus
Type species: Perchnielsenella stradneri (Perch-Nielsen, 1973) Watkins in Watkins & Bowdler, 1984

Farinacci & Howe catalog pages: Perchnielsenella *

Distinguishing features:
Parent taxon (Watznaueriaceae): Placoliths or modified placoliths with R-unit well developed, forming proximal and distal shield elements with opposite senses of imbrication; the V-unit typically forms a narrow distal cycle near the inner edge of the shield. Central-area structures are typically disjunct. Birefringent LM image, in which the V-unit cycle appears only as a thin, dark line.
This taxon: Medium to large, barrel-shaped coccoliths that are highly-birefringent and seen in both side and plan view.

Search data:
TagsLITHS: nannolith-radiate, placolith, SHAPE: circular, cylindrical, hollow, CA: vacant,
CSPH: equant, monomorphic, CROSS-POLARS: rim-unicyclic, R-prominent,
MetricsLith size: 5->9µm;
Data source notes: size range of included species
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): at top of Maastrichtian Stage (100% up, 66Ma, in Danian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Campanian Stage (0% up, 83.6Ma, in Campanian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Burnett, J. A. (1998). Upper Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 132-199. gs V O

Perch-Nielsen, K. (1973c). Neue Coccolithen aus dem Maastrichtien von Danemark, Madagaskar und Agypten. Bulletin of the Geological Society of Denmark. 22: 306-333. gs V O

Watkins, D. K. & Bowdler, J. L. (1984). Cretaceous calcareous nannofossils from Deep Sea Drilling Project Leg 77, southeast Gulf of Mexico. Initial Reports of the Deep Sea Drilling Project. 77: 649-674. gs V O


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Perchnielsenella compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 9-12-2021

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10867 Go to Archive.is to create a permanent copy of this page - citation notes



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