|Daughter taxa (time control age-window is: 0-800Ma)||Granddaughter taxa|
BCs with 3 flanges, but mid-wall flange weakly developed, as ring bead-like nodes; XCs muroliths, similar to BCs.
BCs with proximal flange only, weakly developed inner wall. Coccospheres are highly varimorphic, the apical BCs have a robust central structure, this decreases toward the antapical area where there are BCs without a central structure. CFCs spine-bearing, with bifurcate tip. XCs muroliths.
BCs with 3 flanges and spines or bosses, CFCs spine-bearing, with bifurcate tip. XCs muroliths with spines.
BCs with 3 flanges, CFCs spine-bearing, with notched tip. XCs dome-shaped.
Distinguishing features: BCs - with distal, mid-wall and basal flanges (except S. noroitica type), and/or with low spines (except S. pulchra and S. dilatata type).
XCs - dome-shaped or muroliths.
CFCs - usually spine-bearing with bifurcate spine-tip.
Farinacci & Howe catalog pages: SY pulchra gp [no catalog entry yet]
Morphology: The exothecal cocociths of this group are very diverse, howver, a common feature is that there is no separate central plate formed of a few larger elements, as is seen in most other Syracosphaera exothecal coccoliths. Intead the radial laths are usually multipart and form the entire central structure. The XC laths also protrude beyond the rim to form beaded margin in noroitica & prolongata types.
|Metrics||Lith size: 1.1->8µm; Coccosphere size: 8->70µm;|
Last occurrence (top): Extant Data source: Total of range of species in this database
First occurrence (base): at base of Zanclean Stage (0% up, 5.3Ma, in Zanclean stage). Data source: Total of range of species in this database
Plot of occurrence data:
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