A detailed examination has been made of the Lopingian (Late permian) anmonoid
succession across the Wuchiapingian/Changhsingian boundary of the northern Penglaitan
Section in the Laibin area, South China. Five ammonoid interval zones were identified
via bed-by-bed collection: the Prototoceras-Konglingites, Etoushanoceras-Jinjiangoceras,
Shevyrevites, Penglaites and Pleuronodoceras-Rotodiscoceras zones, in ascending order.The
lower three zones, located in the upper part of the Heshan Formation, are all of
Wuchiapingian age in terms of the associated conodonts, whereas the Penglaites Zone, which
crosses the lithologic boundary between the Heshan and Talung formations,and the uppermost
zone in the lower part of the Talung Formation are of Changhsingian age.  Ammonoid faunal
turnover, from otoceratoid-donnated to Xenodiscoid-dominated faunas, occurred between the
Etoushanoceras-Jinjiangoceras and Shevyrevites zones.  This horizon is slightly lower than
the Wuchiapingian/Changhsingian boundary, which is located between the Shevyrevites Zone
and the Penglaites Zone of the northern Penglaitan Section in the Laibin area, South China.