Early Carnian conodont fauna at Yongyue, Zhenfeng area and its implication for Ladinian-Carnian subdivision in Guizhou, South China

Thus in the study area, the Zhuganpo Formation is generally of early Carnian (Julian 1) age whilst the Wayao Formation probably extends from the Julian 2 into the late Carnian (Tuvalian substage). The Ladinian-Carnian boundary (LCB) cannot be precisely defined due to the absence of the ammonoid Daxatina canadensis and the paucity of conodonts. However, the LCB is unlikely lower than the Yangliujing-Zhuganpo formation contact. The Julian 1-Julian 2 (early Carnian) substages boundary is defined in the uppermost Zhuganpo Formation by the occurrence of basal Julian 2 ammonoid Austrotrachyceras ex gr. A. austriacum and is also evidenced by the disappearance of most short-range Julian 1 conodonts in the overlying Wayao Formation.