Restudy of conodont zonation and evolution across the P/T boundary at Meishan section, Changxing, Zhejiang, China

Abstract

Large conodont samples have been collected from the uppermost Permian and lowermost Triassic (beds 24–29) at the Meishan section — the Global Stratotype Section and Point (GSSP) for the Permian–Triassic Boundary. This new information revises the ranges of some important conodont species in this section. For the first time, usable numbers of Neogondolella specimens have been found from the basal-most Triassic, enabling the establishment of parallel hindeodid and gondolellid zonations through the same section over this interval. In ascending order, the refined hindeodid zones are as follows: Hindeodus latidentatus Zone (bed 24a), Hindeodus praeparvus Zone (24b–26), Hindeodus changxingensis Zone (27a–b), Hindeodus parvus Zone (27c), Isarcicella staeschei Zone (27d–28), Isarcicella isarcica Zone (bed 29 and above). Three revised and newly established Neogondolella zones are proposed. In ascending order these are as follows: Neogondolella yini Zone (bed 24 and below), Neogondolella meishanensis Zone (25–26), Neogondolella taylorae Zone (27a and above). Neogondolella taylorae—a proposed earliest Triassic marker species, first appears in bed 27a, just below specimens of Hindeodus cf. parvus in bed 27b. Three successive conodont faunal assemblages are identified through the Permian–Triassic transitional interval.