Nannotax

Description: Cells non-motile, but coccosphere asymmetrical with an opening. Coccoliths also asymmetrical, distal shield is typically weakly elliptical but with tube and proximal shield offset from centre, otherwise very like Calcidiscus. Proximal shield small, monocyclic.

Remarks: Predominantly deep-photic.

Type species: Oolithotus antillarum.