Coronosphaera HOL type
Classification: Coccolithophores -> Holococcoliths -> flat-topped -> Coronosphaera HOL type
Sister taxa: Calyptrosphaera -flat, Coronosphaera HOL type, Helicosphaera HOL, Poricalyptra, Zygosphaera,
|Daughter taxa: (blue => in age window 0-800Ma) |
| BCs tube simple; distal surface flat, slightly recessed below top of tube; numerous hexagonal/star-shaped pores; central boss. |
CFCs zygoliths, open tube spanned by robust bridge, with low pointed leaf.
| BCs tube flaring, no flange, hexagonal mesh fabric; distal cover flat, hexagonal mesh fabric without larger pores; discontinuous rim formed from two rows of crystallites; boss, prominent, slightly off-centre, with irregular fabric.|
CFCs with arched distal surface rather than a clear bridge.
| BCs with concentric structure and central boss; tube wall with hexagonal crystallite fabric, a row of perforations above base and a variable number of extra perforations.|
CFCs with boss elevated into spine-like structure with three buttresses
| Similar to C. multipora but only 4-6, irregular, pores on distal surface.|
CFCs with bridge elevated into spine-like structure, sometimes with three buttresses
| Monomorphic, liths similar to BCs of C. wettsteinii, but pores more angular, separated by network of straight bars two crystallites wide, also boss smaller, often not central, some liths have two bosses. Weak basal flange.|
| BCs tube about 9 crystallites high, no flange; distal surface flat; hexagonal mesh fabric to tube and distal cover. |
CFCs vaulted with flat hexagonal mesh plates sloping towards centre from each end. Between these plates an irregular area of parallel strings of crystallites occurs.
Citation: Coronosphaera HOL type, sensu Young et al., 2003Rank: species group
Distinguishing features: Dimorphic - usually cavate
BCs with flat distal cover with or without openings; central boss
CFCs; with irregular bridge or distal cover arched upwards
Farinacci & Howe catalog pages:
Biology & life-cycles: Three of these coccosphere types are now known to form associations with Coronosphaera mediterranea, this suggests that C. mediterranea may actually be a group of closely related species which can be separaed in the holococcolith stage but not in the heterococcolith tage (Geisen et al. 2002).
See also: Coronosphaera mediterranea ;
The morphological data given here can be used on the advanced search page. See also these notes
|Metrics||Lith size: 0->0µm; |
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 Gelasian stage). Data source: Total of range of species in this database
Plot of occurrence data:
- Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
- Triangles indicate an event for which a precise placement has been suggested
- Neptune data: this is a higher taxon page so Neptune data is not plotted. For the customisable plot option go to a genus page Parent: flat-topped
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, Special Issue. 1: 1-132. gs :: view :: open