Traces of Augoichnus dituberculatus gen. et sp. nov. on Hypermorphocrinus magnospinosus from the Lower Permian of Cisuralia

Traces of Augoichnus dituberculatus on Hypermorphocrinus magnospinosus and some other crinoids are described from the reef deposits of the Sarginian Horizon near the village of Ryabinovka, in the vicinity of Krasnoufimsk. Usually these are groups of shallow depressions, egg-shaped in outline, 4–5 mm long, similarly oriented, with a marginal groove, paired tubercles, and a deeper subcentral region. Less commonly the depressions are deep and occasionally even can perforate the skeleton. It is possible that these traces were left by gastropods, which could have moved on the surface of crinoids and fed at their expense.