Olladiscoaster catinatus

Olladiscoaster catinatus de Kaenel & Bergen in de Kaenel et al., 2017

Emended Description: Circular species of Olladiscoaster have segments without arms. On the distal side, the distinct sutural ridges are created by the deep cavities. The sutural ridges are raised towards the centre and capped by boomerang-shaped distal covers. The distinct proximal ridges without a knob decorate the bulged proximal side. At the side view, Olladiscoaster catinatus resembles a child’s top.

Olladicoaster catinatus is differentiated from other armless Olladiscoaster with a boomerang shape distal cover, such as Olladiscoaster cruzii and Olladiscoaster asterilithos, lacking proximal knob. Olladiscoaster cruzii has petaloid, whereas Olladiscoaster asterilithos has radiating proximal knobs. The hexagonal shape Olladiscoaster exagonikoasteri also has a boomerang shape distal cover and lacks a proximal knob, but the sutural ridges are almost aligned with the vertices. The sutural ridges bisect the edges at the middle in Olladicoaster catinatus.

De Kaenel, E., Bergen, J. A., Browning, E., Blair, S. A. & Boesiger, T.M. 2017. Uppermost Oligocene to Middle Miocene Discoaster and Catinaster taxonomy and stratigraphy in the circum North Atlantic Basin, Gulf of Mexico and ODP Leg 154. Journal of Nannoplankton Research, 37 (2-3): 215–244.

Varol, O. & Bowman, A. R. 2024. The New Middle Miocene Genus Olladiscoaster, and Related and Associated Discoasters. Grzybowski Foundation Special Publication, 28, 103 pp.