Nannotax Enabling nannofossil research

Description: 6-rayed discoaster with a well developed central area; rays ending in strong short wide bifurcations. There is often a distal knob, and sometimes weak distal ridges on the rays. The proximal side is essentially featureless, although the sutures may be incised.

Remarks: The species shows cniderabe variation in: size,  number of rays (5-7), reltive size of central area, and degree of development of the ray bifurcations. Hay et al. (1967) used this variation to create 5 separate species, all from the Early Miocene of Trinidad. However, these forms intergrade and separating them has not proven useful. A possible exception are forms with small central areas (D. aulakos, D. saundersii). These become more common toward the end of the Early Miocene, and might be separated as an intermediate variety between D. deflandrei and D. exilis.

Original description:

Variants:

Discoaster moorei Bukry, 1971 - asymmetric 5-rayed form.

Discoaster aulakos Gartner, 1967 - smaller central-area and weaker bifurcations, arguably an intermediate form between D. deflandrei and D. exilis.

Synonyms

Discoaster dilatus Hay, in Hay et al 1967

Discoaster divaricatus Hay, in Hay et al 1967

Discoaster nephados Hay, in Hay et al 1967

Discoaster saunder sii Hay, in Hay et al 1967

Discoaster trinidadensis Hay, in Hay et al 1967