On the Anatomical Structures of the Lepidodendralean Stem 'Lepidodendron' tripunctatum from Coal Balls of Taiyuan Formation in Shandong Province, North China

摘要

An anatomically preserved lepidodendralean stem is described from coal balls of the early Early Permian or late Late Carboniferous Taiyuan Formation in Tao-Zao and Yanzhou coal fields from southern Shandong, North China. The stem bears leaf cushions previously assigned into "Lepidodendron" tachingshanense Lee, but is renamed as "Lepidodendron" tripunctatum Stock, et Math, based on the morphology of the leaf cushion in this study. Comparison and relationship between "L." tripunctatum and other anatomically preserved lepidodendralean stems from the middle Late Carboniferous Euramerican and the late Late Carboniferous or early Early Permian Cathaysian floras is made and discussed.