Ginkgoales And Czekanowskiales From The Middle Jurassic In Western Junggar Basin Of Xinjiang, China

Ginkgoales and Czekanowskiales are ones of the most important taxa of the Mesozoic flora all over the world and significant for the study of evolution of the gymnosperms during the geological history. Ginkgoales and Czekanowskiales are abundant in the Middle Jurassic of the western Junggar Basin, Xinjang of China, but they are short of thorough study in their taxonomy during the past. In the present paper, the author studies the cuticles of the two order-rank taxa from the Middle Jurassic in the Baiyang River and Manas River areas of the western Junggar Basin, for the first time. There are 8 genera and 14 species, in total, reported , in which, Sphenobaiera junggarensis, Ginkgo coriacea, Leptostrobus laxiflora and Ixostrobus sp. are found very recently, are studied in detail for the first time. Besides, the cuticles of Ginkgo obrutschewi and Phoenicopsi(sP.)angustifolia are described in detail for the first time, also. On the basis of the characters of the present flora, the author analyses also the geological age, paleogeography and paleoclamite indicated paleobotanically. At the same time, the author summarizes the recent advance in the study of Ginkgoales and Czekanowskiales. In the field work, the author measured the geological section of the Middle Jurassic Xishanyao...