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.
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 |  |  |  | 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.
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 |  |  |  | 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.
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 |  |  |  | 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.
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 |  |  |  | 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.
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 |  |  |  | Varolia sp.
Specimens which cannot be assigned to any established species
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Taxonomy:
Citation: Varolia Bown, 2005Rank: GenusType 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:
| Tags | LITHS: holococcolith, elliptical, hollow, |
| Metrics | Lith 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:
- Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
- Triangles indicate an event for which a precise placement has been suggested
- Neptune data: This is a higher taxon page so Neptune data is not plotted. See also: customisable plot Parent: fossil holococcoliths
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
