Nannotax Enabling nannofossil research

Extant coccolithophore: A common species, with weak preference for oligotrophic areas (Ziveri et al. 2004); coccosphere large, trimorphic with body coccoliths (BCs), spine-bearing circum-flagellar coccoliths (CFCs), and exothecal coccoliths (XCs).
Coccospheres 15-25 µm

Coccolith types:

	Body coccoliths (BCs) - large (4.5-8 µm); mid-wall flange prominent; inner wall-cycle well developed; central area with three concentric cycles of thin radial laths, occasionally incipient spine in centre
	Circum flagellar coccoliths (CFCs) - similar to BCs but with robust bifurcate-tipped spine
	Exothecal coccoliths (XCs) - dome-shaped, rim sub-horizontal, flange-like. Radial cycle formsvertical part of wall, numerous elements with wide slits. Central part formed of several cycles of laths; with a central conical depression.

Life-cycle: There is a well-estabished alternate holococcolith-bearing phase. Holococcoliths previously refered to as = Calyptrosphaera oblonga and Calyptrosphaera pirus, see Cros et al. (2000), Geisen et al. (2002), Saugestad & Heimdal (2002). Since the oblonga-type and pirus-type holococcoliths are well differentiated we suspect that S. pulchra consists of two species which are only differentiable in the holococcolithophore life-cycle stage (Geisen et al. 2002, 2004).

Remarks:

Fossil record: BCs commonly recorded from Pliocene and Pleistocene sediments, reasonably reliable default identification for large (>5µm) Syracosphaera coccoliths.