【摘要】 首次报道我国渐新世银杏属植物叶化石。化石采自黑龙江汤原县太平川剖面宝泉岭组,角质层保存状态良好。叶为下气孔式。上表皮细胞垂周壁平直,平周壁较平。下表皮大量气孔器不规则地散布于脉间区,形成气孔带;气孔密度约为117个/mm2;气孔器为单环式,保卫细胞下陷,侧副卫细胞角质化强烈并形成乳突。当前材料的形态及显微构造特征与古近纪北半球广泛分布的铁线蕨型银杏Ginkgo adiantoides(Ung.)Heer emend.Flo-rin(auctorum multorum)基本一致。这是我国目前已知年代最新的银杏大化石记录,对于探究银杏属在我国新生代的分布、迁徙以及当时相关的古植物地理和气候环境等具有重要意义。更多还原

【Abstract】 For a long time,there is no record of post-Eocene Ginkgo megafossils in China. In the present short note,Ginkgo leaves are reported for the first time from the Oligocene. The fossil leaves,with well-preserved cuticle,were collected from Tai-pingchuan section of Baoquanling Formation of Tangyuan County,Heilongjiang Province. The leaf is hypostomatic. In the upper cuticle,the anticlinal walls of epidermal cells are straight,and the periclinal walls are flat. In the lower cuticle,plenty of stomata randomly distribute in the intercoas-tal zone,forming the stomatal zone with a stomatal density of about 117 per mm2. The stomatal complexes are monocyclic; the guard cells are sunken below the surface and the lateral subsidiary cells are strongly cutinized,forming papillae extending towards the stomatal pit. The gross morphology and microscopic characteristics of the present material are generally comparable with those of Ginkgo adiantoides (Ung.) Heer emend. Florin (auctorum multorum) that widely distributed in the North Hemisphere in the Paleogene. The present Oligocene Ginkgo represents the youngest fossil record of the genus so far known in China. It is of importance for understanding the distribution and migration of the genus Ginkgo,as well as the understanding of related paleophytogeographic and paleoclimatic conditions in the Cenozoic of China.更多还原