Fig. 1: Arm plates of Ophiopetagno paicei and Muldaster haakei from the Silurian of Gotland, Sweden, in comparison to a living relative (Ophiopholis aculeata), and in the context of the local stratigraphic framework12 with localities sampled (Mulde T.: Mulde Tegelbruk), palaeoenvironmental events, and trends in average surface area of the lateral arm plates as an approximation for body size.
From: Miniaturization during a Silurian environmental crisis generated the modern brittle star body plan
Ophiopholis aculeata: lateral arm plate in external (a) and internal (b) views. Vertebra in lateral (c), ventral (d), and distal (e) views. Muldaster haakei: Specimen MnhnL OPH088 (all numerical codes in the figure legend refer to specimen numbers in the MnhnL collection), holotype of M. haakei. Lateral arm plate in external (f) and internal (g) views. Specimen OPH089. Vertebra in lateral (h), ventral (i), and distal (j) views. k Specimen OPH090. Arm segment in ventral view. Ophiopetagno paicei: Specimen OPH087. Lateral arm plate in external (l) and internal (m) views. Specimen OPH092. Vertebra in lateral (n), ventral (o), and distal (p) views. q Specimen OPH93. Lateral arm plate, detail of tentacle notch in internal view.
