Nannotax3 - ntax_cenozoic - convex Nannotax3 - ntax_cenozoic - convex


Classification: ntax_cenozoic -> Holococcoliths -> convex
Sister taxa: tubeless, convex, bridged, flat-topped, septate, open-tube, fossil holococcoliths, U. extant holococcolith

Daughter taxa (time control age-window is: 0-800Ma)Granddaughter taxa
not elevated - height < length
Calyptrosphaera sphaeroidea HOL
Tube merges into cover; irregular crystallites

Syracosphaera pulchra HOL oblonga type
Tube merges into cover; hexagonal mesh fabric

Syracosphaera pulchra HOL pirus type
Tube and cover sharply separated; cover with openings at base

Syracosphaera pulchra HOL galea type
Tube high and well-separated from cover; hexagonal mesh fabric

Calyptrolithina divergens
Tube sharply separated from cover; cover with perforations

elevated - height > length
Calyptrosphaera heimdaliae
Tube and cover sharply separated; cover elevated with large openings at base and an apical perforation

Calyptrosphaera lluisae
Low wall with domal cover, ring of small perforations at base of cover and an apical perforation

Calyptrosphaera radiata
Liths tubular with large openings near base and closed distal end. Coccosphere vari-monomorphic (coccolith height varies)

Flaring tube-shaped coccoliths with distal cover - flosculoliths. Monomorphic.
Flosculosphaera calceolariopsis
Flosculosphaera sacculus

Bulb-shaped coccoliths - gliscoliths. Monomorphic.
Gliscolithus amitakareniae


Citation: Holococcoliths with convex cover over the tube - informal grouping proposed by Young et al., 2003
taxonomic rank: informal group of genera

Distinguishing features:
Parent taxon (Holococcoliths): Haploid life-cycle stages, with liths formed of numerous rhombohedral microcrystals
This taxon: Holococcoliths with tube, covered distally by a convex cover

Farinacci & Howe catalog pages: convex [no catalog entry yet]

Search data:
Lith size: 0.9->3.2µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): Extant. Data source: Total of ranges of the species in this database
First occurrence (base): within Quaternary Period (0.00-2.59Ma, base in Gelasian stage). Data source: Total of ranges of species in this database

Plot of occurrence data:


Young, J. R., Geisen, M., Cros, L., Kleijne, A., Probert, I. & Ostergaard, J. B. (2003). A guide to extant coccolithophore taxonomy. Journal of Nannoplankton Research. S1: 1-132. gs


convex compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 21-4-2024

Taxon Search:
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Short stable page link: Go to to create a permanent copy of this page - citation notes

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