Helicosphaera clarissima Bown, 2005d
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.
Helicosphaera clarissima
Bown, 2005
Late Eocene