The early land plant group zosterophyllopsid is widely reported from the global Silurian to Devonian sediments. The morphological study of this group is fundamentally significant to plant evolution.   

Demersatheca contigua, an endemic zosterophyllopsid of the Early Devonian flora in South China, was thought to have flat fertile organs in previous studies, whilst the new research challenged this perception.  

Recently, a research team led by Prof. XU Honghe, Prof. WANG Yi and PhD student WANG Yao, Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), discovered the species Demersatheca contigua from the Lower Devonian of both Guangxi and Yunnan, southern China and published its morphological study in Review of Palaeobotany and Palynology.  

The plant fossils described in this study include 6 specimens previously attributed to Zosterophyllum contiguum and Z. australianum from the Lower Devonian Posongchong Formation of Wenshan, Yunnan and 11 specimens newly collected from the Lower Devonian Cangwu Formation of Cangwu, Guangxi. With the examinations of these specimens, a better understanding of the fertile morphology of the zosterophyllopsid group, especially of the genus Demersatheca, is reached.  

The structure of the D. contigua strobilus is reconstructed and the generic and specific diagnoses of D. contigua are emended in the aspect of its fertile morphology. The Demersatheca contigua strobilus consists of four rows of decussately-arranged sporangia, the sporangia are biconvex with marginal dehiscence bending towards the strobilus, making the whole strobilus cylindrical-shaped.