Placozygus banneri

Classification: Mesozoic -> Eiffellithales -> Chiastozygaceae -> Placozygus -> Placozygus banneri
Sister taxa: P. banneri, P. fibuliformis, P. spiralis, P. sp.,

Distinguishing features: Small Placozygus (holotype 4.4 µm) with crossbar dark in xpl and almost filling the central area


Citation: Placozygus banneri Lees, 2007
Rank: Species

Farinacci & Howe catalog pages: Placozygus banneri *

Distinguishing features: Small Placozygus (holotype 4.4 µm) with crossbar dark in xpl and almost filling the central area

Morphology remarks: "A small species of Placozygus that has the spiral-rim extinction pattern that is typical of the genus, a distinctive wide, bright inner cycle, and a dark short-axis bar, apparently composed of two blocks, that almost fills the small central area. Differentiation: This new species is distinguished from other placozygids by its wide, bright inner cycle, narrow central area and almost indistinguishable short- axis bar" [Lees 2007]

Size: Holotype dimensions: L = 4.4μm, W = 3.08μm.

Search data:
TagsLITHS: murolith, elliptical, CA: process, bar, V-UNITS: V-prominent, R-UNITS: R-prominent, DETAILS: ca_disjunct, rim-bicyclic,
MetricsLith size: 3.5->5µm;
Sources: holotype and extended
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 Late Campanian Substage (72.05-76.38Ma, base in Campanian 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: Placozygus


    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


    Placozygus banneri compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 4-7-2020

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