Trace Fossils From The Upper Part Of Shiyantou Member,Meishucun,Eastern Yunnan Province

There is a series of controversy about the early origin of life,for example,Entity body fossils is not well consistent with molecular clock data.Fortunately,abundant trace fossils were shown around the Ediacaran-Cambrian boundary,which were different from the body fossils.The Meishucun profile in Yunnan Province covers the EdiacaranCambrian transitional strata,which is characterized by abundant trace fossils which is the very important materials for the evolution of early life.In our study,all research materials come from the upper part of Shiyantou section during Meishucunian Stage.In order to explore the characteristics of the trace fossils,we have conduct and statistically analysis the individual depth and width of macro body trace fossils.In combination with the nutrition of trace fossils type,we also discuss the corresponding environmental factors such as food source.Thus,our main conclusion includes: 1)recorganization of about 7 ichnogenus and 9 ichnospecies such as Gordia marina Emmons,1844,Gordia cf.Maeandria,Helminthopsis isp.,Planolites cf.annularius,Planolites octichnus Chamberlain,1971,Psammichnites gigas,Torell,1868,Taphrhelminthopsis circularis Crimes et al.,1977,Monocraterion tentaculatum Torell,1870,Lorenzinia isp..2)statistical analyses of the individual width and depth of the trace fossils,in which a rise of trace fossils,a differentiation degree of species,and bioturbation were shown in the upper part of Shiyantou section during Meishucunian Stage.3)recorganization of about five ethology,including locomotion trace,dwelling trace,feeding trace,grazing trace,escape trace.