The importance of Hindeodus parvus (Conodonta) for the definition of the Permian-Triassic boundary and evaluation of the proposed sections for a global stratotype section and point (GSSP) for the base of the Triassic

The biostratigraphic Permian/Triassic (P/T) boundary is defined by the first appearance of H. parvus. The first appearance of H. parvus within the cline H. latidentatus-H. parvus is a globally recognizable event in the conodont evolution. The first appearance of H. parvus is not facies related and can be observed both in ammonoid-free shallow-water deposits and in ammonoid-bearing pelagic deposits. H. parvus is a common, easily determinable species known so far from the entire Tethys, Japan, western North America, Boreal realm (Greenland) and the Tethyan margin of Gondwana. H. parvus is the first species with world-wide distribution to appear after the absolute minimum in the faunal diversity indicated by the minimum in δ13C. The Meishan section (South China) contains a continuous, pelagic sedimentary record across the P/T boundary without stratigraphic gaps. It is nearly unaltered thermally (CAI = 1-1.5). Its fossil content (ammonoids, conodonts, foraminifers, bivalves, brachiopods, sporomorphs etc.) and event succession have been thoroughly studied. Absolute age and magnetostratigraphy have also been subjected to intensive studies. The section is readily accessible and under protection of the government. This section is best suitable as a global stratotype section and point (GSSP) for the base of the Triassic. No other section in the world is known to be qualified for defining the P/T boundary in a GSSP. H. parvus made its earliest appearence in the middle part of Boundary Bed 2 (Bed 27) at Meishan. It evolved within Bed 27 from H. latidentatus within a phylomorphogenetic continuum in a continuous and monofacial stratum. The biostratigraphic P/T boundary lies very close to the event boundary (15cm above the event boundary at the base of Boundary Bed 1 = Bed 25, and a few centimetres above the minimum in δ13C in the lower Boundary Bed 2).