Helicosphaera kamptneri

Helicopontosphaera kamptneri Hay & Mohler, 1967

A helicolith with a Type III (Helicosphaera carteri type) blanket, an expanded flange termination, and a central area featuring tiny pores hardly visible. Helicosphaera kamptneri differs from Helicosphaera carteri and Helicosphaera epimikeisporous by its tiny pores. It is distinguished from Helicosphaera paleocarteri and Helicosphaera dyotrypes by having both tiny pores aligned along the axial suture. In Helicosphaera
paleocarteri, both pores aligned off the longitudinal suture, and in Helicosphaera dyotrypes, only one of the pores aligned with the axial suture. Helicosphaera kamptneri exhibits inclined extinction angles of about 52° on the blanket on the distal side and shows length-fast (−) elongation.

Hay, W. W., Mohler, H. P., 1967, Calcareous nannoplankton from Early Tertiary rocks at Point Labau, France and Paleocene-Early Eocene correlations. Journal of Paleontology 41(6), 1505-1541.