Hyoliths from the Bystraya Formation (Cambrian Series 2) of eastern Transbaikalia (Zabaykalsky Krai), Siberia

Abstract The hyolith fauna of the middle Bystraya Formation (Cambrian Series 2) of eastern Transbaikalia (Zabaykalsky Krai), Siberia, includes at least 17 described taxa distributed between the orders Hyolithida and Orthothecida. Species of Microcornus, Parkula, Conotheca, Neogloborilus and Cupitheca are widely reported from Cambrian strata elsewhere. Triplicatella uslonica sp. nov. is known only from Transbaikalia. Dauritheca is proposed as a replacement generic name for the junior homonym Pachytheca, originally described from Xinjiang, China, and its range is extended to Transbaikalia. A conch with prominent comarginal ribs is referred to Salanytheca daurica sp. nov., a genus otherwise known from the early Cambrian of Mongolia and northern Siberia. John S. Peel [john.peel@pal.uu.se], Department of Earth Sciences (Palaeobiology), Uppsala University, Uppsala, Sweden; Alexander P. Gubanov [Alexander.Gubanov@pal.uu.se], Museum of Evolution, Uppsala University, Uppsala, Sweden.