Discoaster misofengaro

Discoaster misofengaro Varol, 2025a

The rosette-shaped species of Discoaster, measuring 8.0 - 10.0 μm, exhibits a distinct concave-convex structure. It consists of 30-40 very narrow segments that are seamlessly joined along their entire length. On the distal side, there is a central depression, while the proximal side features a prominent knob.

Maximum diameter = 8.74 μm (measured in BF); Maximum diameter = 3.63 μm (measured in XPL).

Optical Properties: Discoaster misofengaro shares the optical properties of the genus Discoaster. In the plan view, Discoaster misofengaro shows constant extinction (dim), and in the side view, it displays interference colours due to birefringence in XPL. The species exhibits first-order yellow to second-order blue interference colours from the side-view examination.

The smaller size and strongly concave-convex shape of Discoaster misofengaro and its prominent proximal knob set it apart from Discoaster delicatus.

Unlike Discoaster lenticularis, which lacks a pronounced concave-convex features and a prominent knob, Discoaster misofengaro boasts 30-40 segments (compared to 20-26 in Discoaster lenticularis).

Varol, O. 2025a. A practical guide to optical studies of calcareous nannofossils. Grzybowski Foundation Special Publication. 29: 1-222