Institutional Repository of Xishuangbanna Tropical Botanical Garden
| Four plant fossil species from the Neogene of Southwestern China, Northern Vietnam and their paleoenvironmental implications | |
| Aye Thida Aung | |
| Thesis Advisor | 苏涛 |
| 2020 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 中国科学院西双版纳热带植物园 |
| Degree Name | 理学硕士 |
| Degree Discipline | 生态学 |
| Keyword | 多样性，木贼属，菱科，菱属，中新世，上新世，块茎，花粉 |
| Abstract | 古植物学和古环境研究不仅可以追溯植物过去的分布，同时也可以追溯植物生存与灭绝和其生境之间的关系。本研究报道了三种分别从中国西南部和越南北部发现的新近纪时期的木贼属化石。这些化石的根状茎和块茎都保存的非常好。在本研究中，我们鉴定并详细描述了木贼属的两个化石新种：Equisetum yenbaiense A.T. Aung, T. Su, T.V. Do & Z.K. Zhou, sp. nov.和Equisetum yongpingense A.T. Aung, T. Su & Z.K. Zhou, sp. nov.。Equisetum yenbaiense A.T. Aung, T. Su, T.V. Do & Z.K. Zhou, sp. nov.采自越南的Yenbai省，年代为晚中新世，鉴定特征为四束细长的块茎在一个节点轮生。Equisetum yongpingense A.T. Aung, T. Su & Z.K. Zhou, sp. nov. 采自云南省永平县，年代为晚上新世，鉴定特征为每个节点基本上都有须根，2-4束大的圆柱形块茎在一个节点轮生。Equisetum cf. pratense Ehrhart 采自云南省镇沅县，鉴定特征为三个卵形块茎长在一束，表面具纵脊。根据其现生最近亲缘种的生境推测这三种木贼属植物当时的生境可能是潮湿的。 此外，本研究还对云南永平三营组晚上新世的菱属花粉化石和西双版纳热带植物园的现生菱属花粉进行比对。从总体形态特征和表面纹饰来看，化石类群和现生类群非常相似。菱属通常生活在潮湿的浅水环境中。这可以指示晚上新世云南西部可能是潮湿的环境，而且现在该地区仍有菱属的分布。 关键字：多样性，木贼属，菱科，菱属，中新世，上新世，块茎，花粉 |
| Other Abstract | Paleobotany and paleoenvironmental studies are important to trace plant species distribution in the past and understand species extinction, ecological linkages, between species and their habitats. In this study, three species of fossil Equisetum (Equisetaceae) were reported from the Neogene of southwestern of China and northern Vietnam; fossils were collected from areas that are well known for the occurrence of plant megafossils. Two new fossil species of Equisetum (Equisetaceae) and Equisetum cf. pretense Ehrhart are recorded and described in detail. All species are reported based on well-preserved rhizomes with tubers. Equisetum cf. pretense Ehrhart from the middle Miocene in Yunnan Province, China is characterized by a bunch of three ovate tubers with longitudinal ridges on the surface. Another Equisetum fossil species, Equisetum yenbaiense A.T. Aung, T. Su, T.V. Do and Z.K. Zhou, sp.nov. from the late Miocene of Yenbai Province, Vietnam, is characterized by four bunches of elongate tubers arranged in a whorl on a node. Equisetum yongpingense A.T. Aung, T. Su and Z.K. Zhou, sp. nov. from the late Pliocene in Yunnan is characterized by fibrous bunches of large cylindrical tubers arranged in a whorl on a node. According to the climatic conditions of the habitats of their living relatives, these three species of Equisetum species might have survived in wet and humid environments. Additionally, Trapa pollen grains were investigated from the Upper Pliocene Sanying formation, Yongping, western Yunnan, were investigated. Fossil Trapa grains are recorded and compared with Trapa natans pollen grains from the Xishuangbanna Tropical Botanical Garden. Both of these species have similar morphological characteristics e.g., triangular obtuse in equatorial view and concave in polar view, surface slightly granulated. Trapa usually grows in shallow water under wet and humid climates. This suggests the existence of Trapa in western Yunnan in the late Pliocene and indicates that the climate conditions were similar to those of the present time. Generally, the two genera, including four species, were reported from the Neogene of southwestern China and northern Vietnam, based on detailed morphological comparisons. We provide new fossil evidence for the evolution of plant diversity in the regions. Besides, these new fossil records deepen our understanding of the paleoclimatic background floristic correlation between southwestern China and Southeast Asia. Further paleobotanical investigations are needed to explore the evolution of plant diversity in response to climate changes in the geological past. Keywords: Diversity, Equisetum, Trapa, Miocene, Pliocene, Rhizome tubers, Pollen. |
| Pages | 47 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | https://ir.xtbg.ac.cn/handle/353005/11711 |
| Collection | 西双版纳热带植物园毕业生学位论文 |
| Recommended Citation GB/T 7714 | Aye Thida Aung. Four plant fossil species from the Neogene of Southwestern China, Northern Vietnam and their paleoenvironmental implications[D]. 中国科学院西双版纳热带植物园. 中国科学院大学,2020. |
| Files in This Item: | ||||||
| File Name/Size | DocType | Version | Access | License | ||
| AYE THIDA AUNG.pdf（1603KB） | 学位论文 | 开放获取 | CC BY-NC-SA | Application Full Text | ||
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Edit Comment