Permian brachiopods from the SelongXishan section, Xizang (Tibet), China Part 1: Stratigraphy, Strophomenida, Productida and Rhynchonellida

Abstract

Abstract A brachiopod fauna containing some 42 brachiopod species of 30 identified genera and 2 unidentifiable genera is recorded from the Selong Group of the Selong Xishan section in southern Xizang (Tibet). Various species of Strophomenida, Productida and Rhynchonellida from this fauna are described and revised in this paper. New taxa include Neochonetes (Sommeriella) regularis nov. sp., Taeniothaerus densipustulatus nov. sp., Krotovia inflata nov. sp., Retimarginifera xizangensis nov. sp., Costatumulus tazawai nov. sp. and Neopsilocamara laevis nov. gen. et sp. Brachiopods from the Selong Group and the basal 0.07 m of the Kangshare Formation indicate an age ranging from Capitanian to Changhsingian in terms of the lates three-fold Permian timescale. Three brachiopod assemblages at the Selong Xishan section are recognised. The Marginalosia-Composita Assemblage in the lower part of the Selong Group is considered to be of Capitanian to Wuchiapingian age. The brachiopods in the Chonetella nasuta Assemblage suggest a Wuchiapingian to possibly early Changhsingian correlation. The Martinia-Waagenites Assemblage in the basal part of the Kangshare Formation is late Changhsingian in age. The brachiopod succession of the Selong Xishan section indicates that there is no major hiatus present within the Selong Group and the Permian-Triassic boundary beds.