Distinguishing features:
Parent taxon (Broinsonia): Outer rim of V-units, with slight clockwise obliquity, visible on distal surface and form dark rim in LM; central-area spanned by an axial cross, grill or perforate plate. 3 tiers visible in side view.
This taxon: axial cross and fine grill
Taxonomy:
Farinacci & Howe catalog pages: B. ethmoquadrata * , B. staytonae *
Distinguishing features:
Parent taxon (Broinsonia): Outer rim of V-units, with slight clockwise obliquity, visible on distal surface and form dark rim in LM; central-area spanned by an axial cross, grill or perforate plate. 3 tiers visible in side view.
This taxon: axial cross and fine grill
Morphology:
Size:
Tags | LITHS: placolith, elliptical, CA: cross-axial, grill, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent, |
Metrics | Lith size: 5->7µm; Data source notes: original descriptions & illustrated specimens |
Geological Range:
Last occurrence (top): within Campanian Stage (72.05-83.64Ma, top in Campanian stage). Data source: Original description - so real range may be longer
First occurrence (base): within Campanian Stage (72.05-83.64Ma, base in Campanian stage). Data source: Original description - so real range may be longer
Plot of occurrence data:
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Broinsonia ethmoquadrata compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 24-5-2022
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10122 Go to Archive.is to create a permanent copy of this page - citation notes |
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