摘要
对内蒙古准葛尔旗二叠纪山西组的一种科达叶的角质层，进行了光学显微镜和扫描电镜观察。比较国内外研究较详细的几种科达叶表皮构造，表明当前标本为科达属一新种，命名为内蒙科达（Ｃｏｒｄａｉｔｅｓｎｅｉｍｅｎｇｅｎｓｉｓｓｐ．ｎｏｖ）。
The leaf cuticle of Cordaites neimengensis sp. nov was studied by light and scanning electron microscopy. The specimens were collected from Lower Permian of Zhungeerqi, Inner Mongolia (Neimenggu), China. Comparing with other species of Cordaites, it was a new species of the genus, based on the structure of its epidermis. Cordaites neimengensis sp. nov (Pls.Ⅰ to Ⅲ; Text-fig.1,B) The specimen comprises two incomplete leaves over 16 cm in length. One is about 1.4 cm wide at the lower part and 0.3 cm wide at the upper part, with nearly 29 veins per cm and 3 to 5 interstitials. The width of the other leaf is about 7.5 cm at the lower part and 8.2 cm at the upper part with 25 veins per cm and 3 to 5 interstitials. Epidermis amphistomatic. Epidermal cells of upper cuticle aligned in longitudinal rows, nearly rectangular in shape, about 33.6 to 86.4 μm×10.2 to 28. 8 μm in size. Stomatal apparatus consisting of 2 sunken guard cells surrounded by 2 lateral and 2 polar subsidiary cells. Stomata haplocheillic, about 56.2 μm×45.5 μm in size, usually arranged in short chains, with one polar subsidiary cell (usually 23.1 to 25.4 μm wide, 34.1 to 39.2 μm long in size) shared with 2 consecutive stomata. The polar subsidiary cells round, oblong or rhomboid in shape. The guard cells reniform or bean shaped, usually 9.7 to 11.6 μm wide, 23.4 to 29.1 μm long in size. Density and index of stomata about 18/mm 2 and 3.2%, respectively. Epidermal cells of lower cuticle also nearly rectangular in shape, about 62.4 to 144 μm×9.6 to 16.8 μm in size. Stomata on the lower cuticle, haplocheillic, 40.8 μm wide and 48 μm long in size, with a pair of sunken guard cells, which is bean shaped and surrounded by 2 lateral and polar subsidiary cells. Stomata arranging in parallel bands, typically one, sometimes two. As for the latter, a single row of lateral subsidiary cells (9.2 to 14.4 μm wide, 33.6 to 62.4 μm long in size) is shared with 2 parallel rows of stomata and occasionally also in bands with two rows side by side. In view outside, small papillae on the outer periclinal wall as well as the lateral subsidiary cells. In view inside, some folds along the anticlinal wall but flat about the periclinal wall. Nonstomatic bands usually with 1 to 10 rectangular cell rows. Density and index of the stomata about 209/mm 2 and 27.2%, respectively. Holotype: 9342; Locality: Heidaigou of Zhungeerqi, Inner Mongolia, North China; Age: Lower Permian (Shanxi Formation).
基金
国家自然科学基金
中国科学院生物科学与技术研究特别支持费
古生物与古人类学科基础研究特别支持费
