Three kinds of anatomically_preserved lepidodendralean leaves from Permian coal balls of China were studied. They all have double xylem strands, which is consistent with the genus Sigillariopsis Scott. Compared with the species of Sigillariopsis , they are considered as three new species: S. shanxiensis sp. nov. and S. taiyuanensis sp. nov. from Coal Seam 7 in the upper part of the Taiyuan Formation (lower Lower Permian), Xishan Coal Field, Taiyuan, Shanxi Province and S. guizhouensis sp. nov. from Coal Seam 1 in the Wangjiazhai Formation (upper Upper Permian), Shuicheng Coal Mining District, Guizhou Province. Based on the associated organs of lepidodendraleans other than leaves and the information of the Euramerican lepidodendraleans, the affinities of the three new species of Sigillariopsis are discussed and they are probably leaves of Sigillaria Brongniart. In Euramerican Flora, Sigillaria (including its leaves Sigillariopsis ) mainly lived in the Carboniferous period and in the Cathaysian Flora they lived in the Upper Carboniferous to upper Upper Permian periods in rare localities. The leaves and fertile organs of Sigillaria have not been reported from the Cathaysian Flora to date. Three new species of the Permian anatomically_preserved leaves of Sigillaria not only increase the diversity of the Cathaysian sigillarian but also bear important significance on the evolution of sigillarian plants and the relationship of the Cathaysian and Euramerican lepidodendraleans.
The isolated and anatomically_preserved lepidodendralean leaf cushions were described from coal balls in Wangjiazhai Formation (upper Upper Permian) in western Guizhou Province. These leaf cushions are very similar to Lepidodendron lepidophloides Yao both in size and morphology. They probably belong to the same species in different preservative condition. Comparisons on morphology and anatomy of L. lepidophloides and lepidodendralean leaf cushion genera, such as Lepidodendron, Lepidophloios, Sigillaria and Cathaysiodendron revealed that L. lepidophloides possesses mixed features of all these genera and it can not be assigned into any of them without doubt. It probably represents a new genus. Because the anatomical features of the other parts of the stem as well as the fertile organs related to these leaf cushions are unknown, the specific name L. lepidophloides is adopted. We leave this taxonomic problem open till the relationship between these leaf cushions and the stem and fertile organs become clear. This is the first report on the detailed anatomical features of the Cathaysian lepidodendralean leaf cushions.
This study reports the anatomical structures of a kind of lepidodendralean stem in coal balls from the early Early Permian Taiyuan Formation in Yanzhou Mining District, southwestern Shandong Province, North China. The leaf cushion is slightly rhomboid in outline with a height of 9 - 10 mm and a width of 7.5 9.0 mm and its lower sides are slightly longer than the upper ones. The top and basic angles of the leaf cushion are truncate and the basic angle is slightly elongate. The upper part of the leaf cushion is strongly high-rising. The leaf sear is large and lenticular in shape. The leaf trace is wide and V-shaped in the leaf scar, and horizontally elongate within the leaf cushion. The leaf trace and lateral parichnos strand extend at a nearly horizontal course outward within the leaf cushion. The ligular pit is deep and extends outward at an oblique course and its aperture is located near the top angle of the leaf scar. No infrafoliar parichnos strands are present. The stem is probably siphonostelic and its pith is probably parenchymatous. The primary xylem is exarch with a nearly smooth outer margin. Only the outer cortex is present and it consists of alternately-arranged radial cell bands and gaps within which the are-shaped or V-shaped leaf traces can be seen. The concave side of the leaf trace is toward the center of the stem. No bundle sheath is developed. Periderm is well-developed and consists of phelloderm and phellem in nearly equal thickness. Compared with the lepidodendralean stems of the Cathaysian and Euramerican Floras, the present specimens are most close to an impression-compression species Lepidodendron pulchrum Zhang in morphology of the leaf cushion and they are put into this species temporarily. Whether the present specimens or the type specimens of L. pulchrum are very different from Lepidodendron Sternburg sensu DiMichele, thus the correct nomenclature and classification of L. pulchrum needs to be reconsidered based on the study of better- and anatomically-preserved stems and fertile organs
