Ceratolithoides kamptneri Bramlette & Martini, 1964
The apical cone and horns exhibit distinct optical behaviour. The apical cone appears in constant extinction under crossed polars, showing grey interference colours. In contrast, the horns and the middle row of beaded elements display parallel extinction (extinction angle = 0°) and reach maximum birefringence, producing first‑order white interference colours at 45°.
The calcareous nannofossils exhibit a distinctive architecture, comprising either two or six horns, with a central apical cone. Horns are typically horseshoe-shaped or arrowhead-like in outline, contributing to a symmetrical or radially arranged profile. The apical cone shows considerable variation in height and is often ornamented with longitudinal rows of beading elements, thereby enhancing its structural complexity and taxonomic distinctiveness.
Bramlette, M. N. & Martini, E. 1964. The great change in calcareous nannoplankton fossils between the Maastrichtian and Danian. Micropaleontology. 10(2): 291-322.