Percivalia pearsonii

Classification: Mesozoic -> Eiffellithales -> Rhagodiscaceae -> Percivalia -> Percivalia pearsonii
Sister taxa: P. arata, P. bullata, P. dunkleyjonesii, P. fenestrata, P. hauxtonensis, P. howardii, P. imperfossa, P. pearsonii, P. pontilitha, P. porosa, P. nebulosa, P. sp.,

Distinguishing features: Central area filled by dark axial cross


Citation: Percivalia pearsonii Lees, 2007
Rank: Species

Farinacci & Howe catalog pages: Percivalia pearsonii *

Distinguishing features: Central area filled by dark axial cross

Morphology remarks: "This medium-sized species possesses a narrow, bicyclic rim, a central-area plate, and a central, axially-aligned cross, each bar of which is divided into two. The cross is located in the centre of a central plate. The cross and plate show very low birefringence in XPL. Differentiation: This new species is distinguished from other Percivalia species by its distinctive axial cross and its lack of perforations in the central plate. Remarks: The rim, inner cycle, and characteristically dark central area of this new species are somewhat reminiscent of Percivalia, although scanning electron microscopy is needed to confirm the generic assignment." [Lees 2007]

Size: Holotype dimensions: L = 6.60μm, W = 4.40μm.

Search data:
TagsLITHS: murolith, elliptical, CA: cross-axial, plate, closed, V-UNITS: V-prominent, R-UNITS: R-prominent, DETAILS: rim-unicyclic,
MetricsLith size: 5->7µm;
Sources: holotype +/-1µm
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within Early Maastrichtian Substage (69.91-72.05Ma, top in Maastrichtian stage). Data source: Lees 2007 (original description)
First occurrence (base): within Early Maastrichtian Substage (69.91-72.05Ma, base in Maastrichtian stage). Data source: Lees 2007 (original description)

Plot of occurrence data:

  • (NB There is no histogram as there are no occurrence records for the taxon in the Neptune database) Parent: Percivalia


    Lees, J. A. (2007). New and rarely reported calcareous nannofossils from the Late Cretaceous of coastal Tanzania: outcrop samples and Tanzania Drilling Project Sites 5, 9 and 15. Journal of Nannoplankton Research. 29(1): 39-65. gs :: view :: open


    Percivalia pearsonii compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 11-7-2020

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