A new plant assemblage from the Middle Triassic volcanic tuffs of Pingchuan, Gansu, northwestern China and its paleoenvironmental significance

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• 作者：Fu-Jun Ma ; Qiu-Jun Wang ; Jun-Ling Dong ; Hao-Fei Wang ; Zi-Xi Wang ; Feng-Tai Zhang…
• 刊名：Pal?ontologische Zeitschrift
• 出版年：2016
• 出版时间：June 2016
• 年：2016
• 卷：90
• 期：2
• 页码：349-376
• 全文大小：16,036 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Paleontology
  Geology
  
• 出版者：Springer Berlin Heidelberg
• ISSN：1867-6812
• 卷排序：90

文摘

A new fossiliferous horizon from the Middle Triassic Dingjiayao Formation, Pingchuan District, Gansu Province, China is described. The plant assemblage preserves a diverse community of horsetails, ferns and seeds of unknown systematic affinity. Ferns are the most diverse elements of the assemblage and are also ecologically dominant, while horsetails contribute a smaller component to floristic diversity and have a lower abundance. Here, five fern taxa are assigned to Marantoidea, Symopteris, Neuropteridium, Cladophlebis and Sphenopteris. Also, six species belonging to three horsetail taxa are described from this assemblage, which are assigned to Equisetites, Echinostachys and Neocalamites. Additionally, remains of doubtful botanical attribution comprise Carpolithus seeds. Some of these groups are recorded from the Middle Triassic of China for the first time. The preservation of these fossils suggests that the assemblage was buried autochthonously or para-autochthonously by volcanic ash fall. Fossilization of these specimens occurred rapidly after the specimens embedded in the volcaniclastic sediments. Also the plant assemblage indicates a local riparian environment in a warm, humid climate.KeywordsHorsetailFernMiddle TriassicGansu provinceNorthwestern China