NEW DISCOVERY OF EDIACARAN-TYPE BIOSTRUCTURES AND OF OTHER FOSSILS on THE CENTRAL YANGTZE PLATFORM, CHINA

Setting aside the Lower Ediacaran Doushantuo black-shale-preserved “Miaohe Biota” (see summary by Xiao et al. 2000), Ediacaran-grade fossils have rarely been reported from the South China Plate, except for a finding of a single specimen referred to Paracharnia, which was discovered in a loose float block in the Yangtze River upstream from Yichang in Hubei Province reported by Sun (1986). Only another specimen of an unknown “biostructure” was reported by Xiao et al. (2005) from the Late Ediacaran middle Shibantan beds near Miaohe, ca. 15 km to the NW of the new locality at Wuhe, which is described herein. A third record of a possible body fossil, the spirally coiled Eoandromeda octobrachiata, was recently described by Zhu et al. (2008) from black shales of the Doushantuo Formation, but its metazoan affinity is in doubt. The apparent lack of characteristic discoidal and/or bilaterally symmetric Late Ediacaran-grade body fossils in China is generally attributed to the absence or scarcity of a taphonomically suitable lithofacies, e.g., medium- to coarse-grained siliciclastics, during this time episode in China (Erdtmann et al. 2005). However, locally thinly laminated siltstone beds occur within parts of the Shibantan Member of the Upper Ediacaran (Upper Sinian) Dengying Formation both in the periphery of the Huangling Anticline in Hubei Province as well as in Ningqiang County (Gaojiashan Beds) in southwestern Shaanxi Province. In rhythmically laminated lime-mudstone beds of the Upper Shibatan member near Wuhe, a new discovery of Ediacara-type “biostructures”, e.g. Kullingia concentrica, and of a cloudinid (Sinotubiculites cf. baimatuoensis) near Shuitongya is reported and reinterpreted herein.