Brachiopod assemblages from the Upper Permian and Permian–Triassic boundary beds, South China

Abstract

Uppermost Permian (Changhsingian) brachiopods are abundant and diverse in South China; thus far, 60 genera and 130 species have been described from the Changhsing Formation. Two distinctive brachiopod faunas can readily be identified from a single Changhsingian zone, the Peltichia zigzag–Paryphella sulcatifera Assemblage Zone. The abundance and diversity of the faunas are controlled to a large degree by lithofacies. The Peltichia zigzag, Spinomarginifera alpha fauna occurs in a limestone facies and the Paryphella sulcatifera, Paracrurithyris pigmea fauna occurs in a clastic (siliceous) facies. At many locations in South China, a "mixed fauna," containing Permian-like brachiopods and Lower Triassic ammonoids and bivalves, occurs directly above the Permian–Triassic boundary. The association of Permian elements mixed with Triassic elements suggests that deposition was more or less continuous across the Permian Triassic boundary and that an unconformity does not occur at the boundary in much of South China.