Description: Circular heterococcoliths with a single shield and open central area, surrounded by a collar/tube. Formed of a single cycle of crystal-units with sub-vertical c-axes (Young et al. 1998).

Original description:

	modern
	fossil

Remarks (relation to ceratoliths): A succesion of observations (Alcober & Jordan 1997, Young et al. 1998, Cros et al. 2000, and Sprengel & Young 2000) have shown that these heterococcoliths are formed during an alternate life-cycle stage of Ceratolithus cristatus and so should not be regarded as a discrete species.

Synonyms:

• Neosphaera Lecal-Schlauder 1950
• Craspedolithus Kamptner 1963

Variants: three different forms can be identified in the modern plankton (Kleijne 1993), and may represent discrete species, although given the life-cycle complexities it is simpler to place them all in C. cristatus.

1. large coccolithomorpha type: 6-10 µm across, opening 0.4-0.5x total diameter [= Neosphaera coccolithomorpha Lecal-Schlauder 1950].
2. small coccolithomorpha type: 4-5 µm across, opening 0.35-0.45x total diameter.
3. nishidae type: 4-7 µm across, opening 0.15-0.3x total diameter [=Neosphaera coccolithomorpha var. nishidae Kleijne 1993].