|Daughter taxa (time control age-window is: 0-800Ma)||Granddaughter taxa|
BCs robust, rim wide, ornamented
BCs narrow smooth rim; CFCs with tall spines
BCs small, large central plaque and narrow lath cycle, rim narrow smooth
BCs with broad smooth rim
BCs like S. ossa but with central ring of nodes; CFCs like S. ossa, with flattened spine; XCs not known
Distinguishing features: XCs “undulating” planoliths, confined to imbricate circlet around flagellar pole. CFCs with spines showing calyx with 4-fold symmetry, AACs usually present.
Farinacci & Howe catalog pages:
Morphology: The XCs are highly distinctive and are formed of: 1. Asymmetric flange with variably-developed wing like extensions (directed toward and away from apical pole of coccosphere). 2. Conical central area (concave on distal side, convex on proximal side), with horseshoe shaped slits at either end.
Coccospheres are typically small and somewhat flattened/oblate - i.e. wider than long.
|Metrics||Lith size: 1->3.5µm; Coccosphere size: 3->13µm;|
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:
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