Upper Arenigian to lower Llanvirnian acritarch assemblages from South China: a preliminary evaluation

Acritarchs from the interval corresponding to the late Arenigian and early Llanvirnian in British stratigraphy have rarely been described from China, and they are documented herein for the first time. A biostratigraphic correlation of certain acritarch taxa with the Undulograptus austrodentatus graptolite Biozone, which constitutes the base of the Darriwilian Stage, is still premature for China and elsewhere. According to recent studies on different sections from South China, it appears that at least four distinctive species (Ampullula suetica, Dicrodiacrodium ancoriforme, Hoegklintia rayii nov. comb., Liliosphaeridium intermedium) may characterize an interval that corresponds to levels just below or within the Darriwilian Stage. In this context, the acritarch assemblages of the lower to upper Arenigian and of the lower Llanvirnian sequences from different localities of the Yangtze Platform are described. Four acritarch assemblages are distinguished for this time interval and their possible correlations with other areas are discussed.