Varolia


Classification: ntax_cenozoic -> Holococcoliths -> fossil holococcoliths -> Varolia
Sister taxa: Clathrolithus, Corannulus, Daktylethra, Holodiscolithus, Lanternithus, Multipartis, Octolithus, Orthozygus, Quadrilateris, Semihololithus, Varolia, Youngilithus, Zygrhablithus, Unidentified fossil holococcoliths

Daughter taxa (time control age-window is: 0-800Ma)
Varolia boomeri
Multi-element, cavate, box-like holococcolith with a pointed apical structure. The walls of the box and apical structure comprise narrow, birefringent, crystallographically distinct elements that are birefringent in XPL.
Varolia cistula
Small to medium-sized, thin-walled, box-like holococcolith with a gently curved upper surface. The thin, birefringent walls comprise at least four crystallographically distinct blocks.
Varolia gracilimura
Medium-sized, thin-walled, dome-like holococcolith. The thin, birefringent walls form a proximal plate and a domed upper surface. The dome broadens distally from the basal plate, and is of similar height and width or taller.
Varolia macleodii
Small, thin-walled, cavate holococcolith with a domed upper surface. The cavate central-area space is filled with small, birefringent elements and at least two prominent vertical plates.
Varolia sicca
Small, elliptical to lenticular coccolith with a narrow, birefringent rim (as viewed in light microscope). When orientated at 0° the rim is crossed by narrow N-S and E-W extinction lines.
Varolia sp.
Specimens which cannot be assigned to any established species

Taxonomy:

Citation: Varolia Bown, 2005
Rank: Genus
Type species: Varolia cistula Bown, 2005

Distinguishing features: Cavate, thin walled, box-like holococcoliths usually seen in side view.

Farinacci & Howe catalog pages: Varolia *

Search data:
TagsLITHS: holococcolith, elliptical, hollow,
MetricsLith size: 2.5->6µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): in upper part of Rupelian Stage (74% up, 29.6Ma, in Rupelian stage). Data source: Total of range of species in this database
First occurrence (base): in lower part of Lutetian Stage (35% up, 45.5Ma, in Lutetian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Bown, P. R. (2005d). Palaeogene calcareous nannofossils from the Kilwa and Lindi areas of coastal Tanzania (Tanzania Drilling Project 2003-4). Journal of Nannoplankton Research. 27(1): 21-95. gs V O


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Varolia compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 13-4-2021

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1476 Go to Archive.is to create a permanent copy of this page - citation notes



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