Nannotax Enabling nannofossil research

Description: 6-rayed discoaster; with small central-area; usually with weak distal and proximal bosses. Bifurcations acutely angled in plan-view and wedge-shaped in cross-section. Rays flat and proximal and distal sides virtually identical.

Remarks: This is the dominant Middle Miocene discoaster and like D. deflandrei shows considerable variation in size, strength of bifurcations, central area size etc. Only variants with particlularly strong central area features have been successfully spearated.

Original description:

Variants:

Eu-discoaster protoexilis Theodoridis, 1984 - intermediate to D. deflandrei, large bifurcations, medium central-area. N.B. If this morphotype was distinguished then other names (e.g. D. aulakos Gartner, 1967), would have priority;

Discoaster signus Bukry, 1971 - form with well developed bifurcations.

Discoaster subsurculus Gartner, 1967 - with weakly trifurcate tip, due to bifid proximal extensions in centre of bifurcations. This morphotype can be quite distinctive but does not seem to be consistently developed.