Discovery of Cathaysiodendron Lee from the Early Carboniferous of Jingyuan,Gansu,western China

As one of the representative members of the Late Palaeozoic Cathaysian flora,Cathaysiodendron has been previously recorded from the Early Permian Taiyuan and Shanxi Formations in north China.The species of Cathaysiodendron presented here are from the lower member of Chouniugou Formation of Ciyao,Jingyuan,Gansu.The overlying marine beds yield fusulinids that are of Visean age in western Europe and conodonts of the Datang Stage in south China,so that the age of the bed containing Cathaysiodendron as Visean,Early Carboniferous,is well constrained.Such a record of Cathaysiodendron is significant in terms of Carboniferous phyto-geography and the evolution of the Cathaysian Lepidophytes.A new species,Cathaysiodendron jingyuanense Wang&Wu sp.nov.is described and a second one mentioned.