Uniplanarius


Classification: Mesozoic -> Nannoliths inc sedis -> Polycyclolithaceae -> Uniplanarius
Sister taxa: Eprolithus, Radiolithus, Farhania, Lithastrinus, Uniplanarius, Quadrum, Micula, Palaeomicula,

Distinguishing features: Stellate (triradiate or tetraradiate) nannoliths with three or four ray-like elements; there may be a small central diaphragm.


Daughter taxa: (blue => in age window 0-300Ma)
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 with four rays with relatively short free length.
Uniplanarius with four narrow rays with relatively long free length.
Uniplanarius with three rays.
Specimens not identified to species level

Taxonomy:

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

Farinacci & Howe catalog pages: Uniplanarius *

Distinguishing features: Stellate (triradiate or tetraradiate) nannoliths with three or four ray-like elements; there may be a small central diaphragm.


Morphology remarks: 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. 

Geological Range:
Last occurrence (top): within Maastrichtian Stage (66.04-72.05Ma, top in Maastrichtian stage). Data source: Total of range of species in this database
First occurrence (base): within Santonian Stage (83.64-86.26Ma, base in Santonian 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. (Editor), Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publications Series. Chapman & Hall, London, pp. 132-199.

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


nannotaxlogo400px

Uniplanarius compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 22-7-2018

Taxon Search:
Advanced Search

Go to Archive.is to create a permanent copy of this page - citation notes



Comments (0)

No comments yet. Be the first!

Add Comment

* Required information
1000
Captcha Image
Powered by Commentics