|Daughter taxa (time control age-window is: 0-800Ma)||Granddaughter taxa|
Monomorphic - cavate
Coccoliths with broad rim and recessed distal cover without boss
Monomorphic; liths solid - formed of layers of crystallites in rhomboid array
Coccolith distal surface with central boss and varying number of depressions.
Helicosphaera HOL catilliferus type
Helicosphaera HOL confusus type
Helicosphaera HOL ponticuliferus type
Helicosphaera pavimentum HOL
Dimorphic - liths cavate
BCs flat topped with large openings in tube and variable openings in distal surface; tiered wall fabric; low transverse ridge.
CFCs helladoliths - ridge of BCs is extended into prominent leaf, no openings in tube.
Syracosphaera aurisinae HOL
Syracosphaera gaarderae HOL
|S. mediterranea HOL type|
Dimorphic - usually cavate
BCs with flat distal cover with or without openings; central boss
CFCs; with irregular bridge or distal cover arched upwards
Syracosphaera histrica HOL
Syracosphaera mediterranea HOL gracillima type
Syracosphaera mediterranea HOL hellenica type
Syracosphaera mediterranea HOL marisrubri type
Syracosphaera mediterranea HOL wettsteinii type
Dimorphic; liths semi-solid - formed of concentric rings of crystallites.
BCs flat topped with node or ridge on distal surface, rather than a true bridge.
CFCs similar with transverse bridge or leaf.
Parent taxon (Holococcoliths): Haploid life-cycle stages, with liths formed of numerous rhombohedral microcrystals
This taxon: Holococcoliths with tube, covered distally by a flat cover
Farinacci & Howe catalog pages: flat-topped [no catalog entry yet]
Ecology & Biogeography
Biology & life-cycles
|Lith size: 1.6->3.3µm;|
Last occurrence (top): Extant. Data source: Total of range of species in this database
First occurrence (base): at base of Gelasian Stage (0% up, 2.6Ma, in Piacenzian stage). Data source: Total of range of species in this database
Plot of occurrence data:
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