Discoaster self-trailiae Varol & Bowman, 2024
The hexagonal species have segments with very short arms, distinct ridges with a petaloid knob on the proximal side and sutural ridges created by the deep cavities on the distal side. The sutural ridges are raised towards the centre and capped by boomerang-shaped distal covers.
In honour of Dr Jean Self-Trail, Nannofossil specialist, Geological Survey, Reston, VA, USA.
Maximum diameter: 7.74 µm, Diameter of central area: 5.20 µm, Length of the arms: 1.27 µm, Maximum height: 4.59 µm, Diameter of petaloid proximal knob: 3.33 µm, Hight of the petaloid knob: 1.16 µm (measurements from bright field micrograph).
Discoaster self-trailiae differs from Discoaster artatus, Discoaster virginianus and its variant, Discoaster gamberi, by having a petaloid proximal knob. In contrast, Discoaster artatus lacks a proximal knob, and Discoaster virginianus has a hexagonal proximal knob.
Varol, O. & Bowman, A. R. 2024. The New Middle Miocene Genus Olladiscoaster, and Related and Associated Discoasters. Grzybowski Foundation Special Publication, 28, 103 pp.