The phytogeographic significance of Early Miocene mosses from Weichang area, Hebei Province

Based on the study of fossils and modern distribution of mosses Leptodictyum riparium, Drepanocladus subtrichophyllus, Amblystegium varium from the Guangfayong section, Weichang area, Hebei Province, the authors found that these mosses first appeared in Weichang area in the Early Miocene (22.1Ma), and they were possibly derived from Eastern Asia of Laurasian. Then, the mosses spread eastward to North America through Beringia and westward to Western Europe along Eurasia. Until the Holocene, they were mainly distributed in the North Hemisphere. Mosses of Leptodictyum riparium and Amblystegium varium further spread southward to South America and Australia since the Holocene, and gradually formed modern distribution framework, and the geographical distribution framework of Drepanocladus trichophyllus was formed in Holocene. The phytogeographical significance concerning origin and spread of these mosses is discussed in this paper.