Nannotax Enabling nannofossil research

Description: Apical spine very well-developed. Lateral elements nearly as large as proximal elements.

Remarks: S. heteromorphosus has a well developed quadrate base, in which the the upper part is nearly as large as the proximal part, which distinguishes it clearly from S. belemnos. Also the spine typically has a rather bulbous base in contrast to the straight-sided S. belemnos.

Size: Length 5-15 microns, varies considerably in all populations, possibly in part due to diagenetic overgrowth. Width usually c. 3-5 microns.

Range: NN4-5 (but rather prone to reworking).