Pickelhaube umbellatum

Pickelhaube umbellatum Bergan, 1994

In plan view under crossed polars, the base of the coccolith exhibits constant extinction, indicating that the optic axis is perpendicular to the microscope stage, whereas the distal process shows first-order white interference colours with length-slow (+) elongation.

In side view, both the base and the distal process show parallel extinction (extinction angle 0°). The distal process exhibits first-order greyish-white interference colours, whereas the base displays first-order yellowish-white interference colours.

In plan view, the coccolith has a circular to subcircular base that supports a distal process. In side view, the base resembles a loxolith, with a proximal rim and an outwardly flaring wall.

The generic and familial assignment to Pickelhaube and Cretarhabdaceae remains uncertain.

Bergen, J. A. 1994. Berriasian to early Aptian calcareous nannofossils from the Vocontian Trough (SE France) and Deep Sea Drilling Site 534: new nannofossil taxa and a summary of low-latitude biostratigraphic events. Journal of Nannoplankton Research. 16(2): 59-69.