Trace fossils from the Permian Lopingian Talung Formation at the northern Penglaitan section of Laibin area, South China: Ichnology, palaeoenvironment, and palaeoecology

Abstract

The end‐Permian mass extinction was the largest biotic crisis in the Phanerozoic. Previous studies of this catastrophe have mainly concentrated on geochemistry or body fossil records. The Changhsingian Talung Formation strata exposed in the Penglaitan section, the Global Stratotype Section and Point for the Guadalupian−Lopingian boundary in Laibin, South China, yield abundant trace fossils that have not been systematically described yet. Herein, we report abundant ichnotaxa from the Talung Formation, including 12 ichnospecies in 10 ichnogenera: Didymaulichnus isp., Helicorhaphe tortilis, Nereites isp., Palaeophycus isp., Planolites beverleyensis, Planolites montanus, Protovirgularia dichotoma, Protovirgularia longespicata, Rusophycus isp., Skolithos linearis, Thalassinoides isp., and Treptichnus isp. They can be assigned to two ichnoassemblages: the Nereites−Planolites (beds 18–45) and Protovirgularia−Skolithos (beds 46–59) ichnoassemblages. Ichnological and sedimentological features indicate that the former ichnoassemblage was probably developed in a deep‐marine turbidite setting, while the latter ichnoassemblage represents an ichnofossil record from a shallow marine environment, that is, subtidal to supratidal zones. In addition, the continuous ichnological records spanning from the Wuchiapingian to Changhsingian, together with facies features show a distinct regression, and they also indicate that diverse trace makers, such as arthropods, bivalves, and worms may have inhabited the Lopingian ocean, with no sign of the long‐term environmental deterioration in the studied area.