New Research Progress on the Paleoflora in the Earliest Triassic of Western Guizhou and Eastern Yunnan,South China

Early Lower Triassic plants are little known in China,especially in South China.This paper presents the paleofloral assemblage from the top of Xuanwei and the lower of the Kayitou Formations in western Guizhou and eastern Yunnan,China.Fossil plants in this area(Annularia shirakii,Lobatannularia sp.,Paracalamites stenocostatus,Gigantopteris sp.,Pecopteris sp.,which are all the Permian relicts) from the bottom of the Kayitou Formation described by other people in 1970s are covered.In addition,many important new fossil plants in the evolution during the Permian-Triassic interval,such as Isoetes Annalepis(including A.zeilleri,A.brevicystis),Peltaspermacae Peltaspermum(including P.martinsii,P.lobutalum,P.sp.),Lepidodendron and Stigmaria and so on are also reported.Both the new type and the Gigantopteris-flora relicts are characterized with the Early Triassic Induan paleofloral features in South China.This paleofloral assemblage contains 31 species in 14 genera.These fossil plants are in association with an early Lower Triassic marine fauna(Bivalves,Ostracods,Brachiopods and Ammonites).So the geological age of this paleoflora is Early Triassic Induan stage,while the FAD of Annalepis is regarded as the marker,representing the beginning of Triassic.Based on analyzing paleoflora and limnology of the top of Xuanwei and the lower of Kayitou Formations,it is concluded that tropical and humid conditions persisted in western Guizhou and eastern Yunnan throughout the Permian and Earliest Triassic.