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:
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:
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.
Size:
Ecology & Biogeography
Biology & life-cycles
Phylogenetic relations
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 |
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): in upper part of Santonian Stage (67% up, 84.5Ma, in Santonian stage). Data source: Total of range of species in this database
Plot of occurrence data:
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. gsReferences:
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Uniplanarius compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 30-1-2023
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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