Nannotax3 - ntax_mesozoic - Uniplanarius Nannotax3 - ntax_mesozoic - Uniplanarius

Uniplanarius


Classification: ntax_mesozoic -> Braarudosphaerales -> Polycyclolithaceae -> Uniplanarius
Sister taxa: Eprolithus, Radiolithus, Farhania, Lithastrinus, Uniplanarius, Quadrum, Micula, Palaeomicula

Distinguishing features:
Parent taxon (Polycyclolithaceae): Nannoliths composed of two superposed wall cycles and a central-area which may be closed, open and vacant, or spanned by a diaphragm-like structure. Elements have tangential c-axis orientation.
This taxon: Stellate (triradiate or tetraradiate) nannoliths with three or four ray-like elements; there may be a small central diaphragm.


Daughter taxa (time control age-window is: 0-800Ma)
Uniplanarius clarkei
Small, square Uniplanarius with rounded corners, formed from four blocks joined along axial sutures that are marked in XPL by relatively broad zones of darker birefringence, together resembling the blades of a propeller. The outer edges of the nannolith may show slightly higher birefringence.
Uniplanarius gothicus
Uniplanarius with four rays with relatively short free length.
Uniplanarius sissinghii
Uniplanarius with four narrow rays with relatively long free length.
Uniplanarius trifidus
Uniplanarius with three rays.
Uniplanarius sp.
Specimens not identified to species level

Taxonomy:

Citation: Uniplanarius Hattner & Wise, 1980
taxonomic rank: Genus
Type species: Tetralithus gothicus Deflandre, 1959

Farinacci & Howe catalog pages: Uniplanarius *

Distinguishing features:
Parent taxon (Polycyclolithaceae): Nannoliths composed of two superposed wall cycles and a central-area which may be closed, open and vacant, or spanned by a diaphragm-like structure. Elements have tangential c-axis orientation.
This taxon: Stellate (triradiate or tetraradiate) nannoliths with three or four ray-like elements; there may be a small central diaphragm.


Morphology:

The genus was erected by Hattner and Wise (1980) for planar, radial nannoliths composed of three or four elements. They considered Quadrum (based on the Q. gartneri type species) to be a junior synonym of Micula and their Uniplanarius concept included Quadrum-like taxa. Varol (1992) considered that these nannoliths were constructed from two superposed wall cycles with a narrow median diaphragm, but evidence for this is equivocal.
Like most Polycyclolithaceae Uniplanarius shows tangential crystalographic c-axes not radial. this is very useful for positively identifying them and distinguishing them from inorganic crystallites. 

Search data:
LITHS: nannolith-radiate, quadrate, star-shaped, triangular, CA: closed, CROSS-POLARS: T-prominent,
Lith size: 3->25µm;
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 Late Maastrichtian Substage (100% up, 66Ma, in Danian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within UC12 zone (83.96-85.30Ma, base in Santonian stage). Data source: Total of ranges 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 O

Hattner, J. G. & Wise, S. W. (1980). Upper Cretaceous calcareous nannofossil biostratigraphy of South Carolina. South Carolina Geology. 24: 41-117. gs


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Uniplanarius compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 20-4-2024

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=11286 Go to Archive.is to create a permanent copy of this page - citation notes
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