Nannotax Enabling nannofossil research

Description: Coccolith structure - coccoliths are open tubes with internal septae (walls). The outer tube wall shows hexagonal fabric and the crystallites have radial c-axes (birefringent in plan view in LM). The fabric of the septae is not obviously different but they are non-birefringent in plan view in LM and so the calcite crystallites must have vertical c-axes.

Coccospheres monomorphic, nearly spherical.

Coccolith form - the internal septae define 4-6 pores, tube 10-15 crystallites high, castellated, higher where it meets internal walls. Base open.

Remarks:

Size: Liths 2-3 µm long.

Life-cycle: The association of this holococcolith with the large Calcidiscus leptoporus (sensu lato) morphotype is still based on a single specimen, but it is an exceptionally clear combination coccosphere (Geisen et al. 2002).

Previous assignment: Syracolithus quadriperforatus (Kamptner 1937) Gaarder 1962

Images from the modern plankton: