云南腾冲上新统植物油丹Alseodaphne hainanensis Merr.表皮微细构造研究

EPIDERMAL MICROSTRUCTURAL STUDIES ON PLANT ALSEODAPHNE HAINANENSIS MERR. FROM THE PLIOCENE OF TENGCHONG IN YUNNAN PROVINCE

研究的樟科植物化石油丹(Alseodaphne hainanensis Merr.)采于云南腾冲上新统芒棒组,它在滇西地区为首次发现。对其进行了大量的实验分析,揭示了其表皮微细构造特征。通过与现生油丹表皮构造和叶结构特征的对比分析,在宏观和微观两方面证实了该化石归属的正确性。现生Alseodaphne hainanensis Merr.分布范围的缩小显示滇西从上新世—现代气候逐渐变冷,上新世的气候比现在温暖。化石Alseodaphne hainanensis Merr.地理分布区的扩大和地质时代的延伸,为植物的发展演化和推论古气候提供了宝贵材料。

Alseodaphne hainanensis Merr. of Lauraceae in this study was collected from the Pliocene Mangbang Formation in Tengchong, Yunnan Province. It is found for the first time in this region. The epidermal microstructural characteristics of this species are investigated based upon extensive laboratory analysis. A detailed comparison of the cuticle and leaf architecture between the fossil and its living equivalent shows that our fossil material belongs to Alseodaphne hainanensis Merr. based on the morphology and epidermis. The reduction of distribution area of Alseodaphne hainanensis Merr. indicates that the temperature gradually decreased from Pliocene to present and the Pliocene climate was warmer than present-day in the area of Western Yunnan. The enlargement of geographical distribution and the extension of geological age of fossil Alseodaphne hainanensis Merr. provide precious materials for the deduction of the development and evolution of plants and palaeoclimate conditions.