Discoaster sanmiguelensis Varol & Bowman, 1981
Emended description: Six-segmented species have a large central area decorated with prominent sutural ridges created by deep cavities on the distal side. In contrast, proximal ridges construct a platform created by ridges embellishing the bulging proximal side. The arms are much shorter than the diameter of the central area (about half) and have parallel-sided free lengths that terminate in notches. A careful focus is required to identify this species because a slight tilt can create a unique look; restricting the description in one orientation may create conflicting strati-graphic ranges.
Discoaster sanmiguelensis differs from similar size Discoaster musicus by having a proximal platform created by ridges, whereas proximal ridges meet at the middle of the central area in Discoaster musicus. Discoaster sanmiguelensis is distinguished from Discoaster vandekampiorum by having segments with non-tapering arms.
Varol, O. & Bowman, A. R. 2024. The New Middle Miocene Genus Olladiscoaster, and Related and Associated Discoasters. Grzybowski Foundation Special Publication, 28, 103 pp.