The Rostroconch Family Bransoniidae from the Early Permian Shakhtau Reef Massif (Mollusca, Southern Cis-Urals)

Abstract

For the first time, rostroconchs of the family Bransoniidae are described from the Lower Permian deposits of the Cis-Urals. The described assemblage includes three new species of three genera, of which two genera are new: Hoarepora uralica sp. nov., Ashaconcha rara gen. et sp. nov., and Agidelia magnifica gen. et sp. nov. The paper clarifies the systematic position of the family Bransoniidae, its diagnosis and composition, as well as the diagnosis and species composition of the genus Hoarepora Mapes in Mazaev, 2022. The species described here are the most ancient representatives of the family Bransoniidae, which were discovered on the territory of the East European Craton and the Urals. In general, taking into account the previously described representatives of Arceodomus, the Early Permian assemblage of rostroconch mollusks of the Southern Cis-Urals suggests a permanent paleogeographic connections of the Ural Strait in the Asselian and Sakmarian centuries with the basins of North America and the Tethyan Realm.