Paper Number: 3618
The fossil plants from the Middle Triassic Linjia Formation in Benxi of eastern Liaoning, China and its paleoclimatic implication
Zhang Y.1,2, Zheng S. 0L.1,2 and Wang Y. D. 1,3
1. College of Paleontology, Shenyang Normal University, Shenyang 110034, China; zhangyihzlmh@synu.edu.cn
2. Key Laboratory for Evolution of Past Life in Northeast Asia, MLRC, Shenyang 110034, China
3. Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China
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The Middle Triassic flora of eastern Liaoning is represented by fossil plants collected from the Linjia Formation of the Linjiawaizi in Benxi of eastern Liaoning, China. The Linjia flora is very spectacular because its components are complicated, representing the only one well-known fossil flora of the Middle Triassic age in NE China. Both first recorded typical elements in Paleozoic, such as Lobatannularia, Taeniopteris, Pterophyllum, Psygmophyllum, Pecopteris lativenosa, P. orientalis and P. candolleana as well as typical Mesozoic ones, such as Neocalamites, Danaeopsis, Symopteris, Scytophyllum, Thinnfeldia, Sagenopteris, Sinozamites, Yabeiella, Sphenobaiera, Podozamites and Albertia are documented in this flora. Among them, Lobatannularia, Taeniopteris and Scytophyllum are typical elements from the Northern Hemisphere. The flora also includes some interesting taxa, for example, Benxiopteris, which is similar to Dicroidium in the basic leaf structure, but different in reproductive organs; Yabeiella is a typical element from the Southern Hemisphere. The flora also includes some components which are difficult to be assigned, such as Symopteris, which is very similar to the Late Paleozoic element, Fascipteris. In this flora, two specimens with their counterparts preserved, probably represent the Gigantopteris. In one of these two specimens, scars possibly representing the areas of ovule or seed attachment are also preserved. Cathaysian elements, e.g., Lobatannularia, Taeniopteris, Gigantopteris? and Pecopteris lativenosa mixed with typical Mesozoic components in this flora indicate that the distribution area of the Linjia flora probably represents the known final extinction area of the relict Cathaysian elements in the world. Because the distribution area of the flora was located in the northeastern North China Plate in Middle Triassic, which was controlled by the special warm and humid coast climate, it is reasonable for the relict Cathaysian elements to survive in that time.
The work was supported by the National Science Foundation of China (31470324) .
Keywords: Middle Triassic, eastern Liaoning, Linjia flora, relict Cathaysian elements, Paleoclimate