Geological Range: Last occurrence (top): within NP12 zone (50.50-53.70Ma, top in Ypresian stage). Data source: [PRB rough estimate] First occurrence (base): within NP6 zone (58.97-59.54Ma, base in Selandian stage). Data source: [PRB rough estimate]
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: S. moriformis group
Bown, P. R. (2005d). Palaeogene calcareous nannofossils from the Kilwa and Lindi areas of coastal Tanzania (Tanzania Drilling Project 2003-4). Journal of Nannoplankton Research. 27(1): 21-95. gsVO
Sphenolithus acervus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 24-7-2021