A further study of Zosterophyllum sinense Li and Cai (Zosterophyllopsida) based on the type and the new specimens from the Lower Devonian of Guangxi, southwestern China

Abstract

Zosterophyllum sinense Li and Cai was reported in 1977 from the Lower Devonian Cangwu Formation, eastern Guangxi of China but was rarely acknowledged by authors for its obscure original description. Based on the re-observations to the type specimens and newly-collected specimens of Z. sinense, its detailed morphological information is revealed. Zosterophyllum sinense consists of tufted rooting system and axes, sporangia with long and straight stalks and two unequal valves, are helically and loosely arranged forming the terminal spikes. By far Z. sinense is only reported from the Lower Devonian of Guangxi, palaeogeographically belonging to the Cathaysia Block, a sub-region of the whole South China Block. An Early Devonian floristic distinction is suggested by the plant components between the Yangtze and Cathaysia blocks.