The Early Permian Angaran flora from the northeastern margin of Tuha basin and its implications for palaeoclimate

A large number of fossil plants were collected from the Lower Permian Yierxitu Formation in the vicinity of Erdaogou Village, Tianshan Town, Hami City on the northeast margin of Tuha basin. A total of five genera and thirteen species have been identified, including three undetermined species. Most of the florae are of Codaitopsida, and almost all of them are common elements of Angaran flora. The Angaropteridium-Noeggerathiopsis-Nephropsis plant assemblage has been established, and its age is considered to be Early Permian based on contrast with other assemblages. The composition of flora and leaf physiognomy show that the study area was located in a relatively warm and humid temperate climate with periodic drought to wetness shift and annual seasonal variations in the Early Permian.