Helicosphaerella orientalis

Helicosphaera orientalis Black, 1971c

Small sub-quadrate helicolith having an asymmetrical blanket (Type II, Helicosphaerella recta type), truncated flange termination and a closed central area. The widely separated small, irregular pores on the holotype is attributed to the artefact of adverse preservational effect.

Helicosphaerella orientalis is differentiated from Helicosphaerella philippinensis Müller (1981) Varol, n. comb. by having a closed central area whereas the latter has an inverse bar in the central area.

Black, M., 1971c. The systematics of coccoliths in relation to the paleontological record. In: Funnell, B. M., Riedel, W. R. (eds), The Micropaleontology of the Oceans. Cambridge University Press, Cambridge pp. 611-624.

Müller, C., 1981. Beschreibung neuer Helicosphaera-Arten aus dem Miozän und Revision biostratigraphischer Reichweiten einiger neogener Nannoplankton-Arten. Senckenbergiana Lethaea 61, 427-435.