Two Species of Zosterophyllum from South China and Dating of the Xujiachong Formation with a Biostratigraphic Method  

作　　者：WANG Deming 

机构地区：[1]Key Laboratory of Orogenic Belts and Crustal Evolution, Department of Geology, Peking University, Beijing 100871

出　　处：《Acta Geologica Sinica(English Edition)》2007年第4期525-538,共14页地质学报（英文版）

基　　金：Acknowledgements This study is supported by the National Natural Science Foundation of China （grants 40302001 and 40232019）; a foundation for the Author of National Excellent Doctoral Dissertation of China （200429）.

摘　　要：ZosterophyUum longa sp. nov. is reported from the Lower Devonian Pingyipu Formation, Jiangyou District, northern Sichuan of China. This new plant has vertically elongate sporangia differing from all known species of Zosterophyllum, demonstrating morphological variations in Zosterophyllophytina. New materials of Zosterophyllum yunnanicum from the Lower Devonian Xujiachong Formation, Qujing District, eastern Yunnan of China show that fertile axes of this species are anisotomous or pseudomonopodial or K-shaped in branching. Sometimes fertile lateral axes are very short and bear an axillary axis at the dividing point. Distinct thickening occurs along the whole margin of a sporangium, with sporangial lobes undeveloped. The evolution of ZosterophyUum is tentatively discussed. A biostratigraphic method of Gerrienne and Streel is introduced and applied to dating of the Lower Devonian Xujiachong Formation, which is considered as of the late Pragian-early Emsian.ZosterophyUum longa sp. nov. is reported from the Lower Devonian Pingyipu Formation, Jiangyou District, northern Sichuan of China. This new plant has vertically elongate sporangia differing from all known species of Zosterophyllum, demonstrating morphological variations in Zosterophyllophytina. New materials of Zosterophyllum yunnanicum from the Lower Devonian Xujiachong Formation, Qujing District, eastern Yunnan of China show that fertile axes of this species are anisotomous or pseudomonopodial or K-shaped in branching. Sometimes fertile lateral axes are very short and bear an axillary axis at the dividing point. Distinct thickening occurs along the whole margin of a sporangium, with sporangial lobes undeveloped. The evolution of ZosterophyUum is tentatively discussed. A biostratigraphic method of Gerrienne and Streel is introduced and applied to dating of the Lower Devonian Xujiachong Formation, which is considered as of the late Pragian-early Emsian.

关 键 词：Zosterophyllum longa sp. nov. Z. yunnanicum biostratigraphic method Early Devonian Xujiachong Formation South China 

分 类 号：P54[天文地球—构造地质学]