Geological Range: Last occurrence (top): within Tortonian Stage (7.25-11.62Ma, top in Tortonian stage). Data source: First occurrence (base): within Aquitanian Stage (20.44-23.03Ma, base in Aquitanian stage). Data source:
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
(NB There is no histogram as there are no occurrence records for the taxon in the Neptune database) Parent: Cystophormis
References:
Cystophormis petrushevskayae compiled by the radiolaria@mikrotax project teamviewed: 8-2-2026