|Daughter taxa (time control age-window is: 0-800Ma)|
Ring-shaped, broadly elliptical, non-birefringent holococcolith with multiple (~7-11) thorn-like projections around the outer edge. Morphology clearest in phase constrast illumination where outer rim shows high relief.
Small to medium sized elliptical coccolith with a broad rim and narrow vacant central area. The rim is thick and ragged in overall appearance.
Specimens which cannot be assigned to any established species
Distinguishing features: Discoidal holococcoliths with large central openings and marginal perforations or indentations; non-birefringent in plan view.
Farinacci & Howe catalog pages: Corannulus * , Diademopetra * , Guttilithion *Search data:
|Tags||LITHS: holococcolith, asymmetric, CA: vacant, CROSS-POLARS: 1ou, V-prominent,|
|Metrics||Lith size: 4->10µm;|
Last occurrence (top): in lower part of Rupelian Stage (17% up, 32.9Ma, in Rupelian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Ypresian Stage (0% up, 56Ma, in Ypresian stage). Data source: Total of range of species in this database
Plot of occurrence data:
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