青藏高原柴达木盆地中新世单籽豆属(Podocarpium)化石的发现及其生物地理学意义  

The discovery of Podocarpium from the Miocene of Qaidam Basin and its biogeographic implication

作　　者：王雪莲 苗运法 牛改红 周莹莹 杨永恒 张腾 赵永涛 孟庆泉 宋春晖 张扬 WANG Xuelian;MIAO Yunfa;NIU Gaihong;ZHOU Yingying;YANG Yongheng;ZHANG Teng;ZHAO Yongtao;MENG Qingquan;SONG Chunhui;ZHANG Yang(Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,Gansu;University of Chinese Academy of Sciences,Beijing 100049;Key Laboratory of Resources Environment and Sustainable Development of Oasis,College of Geography and Environmental Science,Northwest Normal University,Lanzhou 730000,Gansu;College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,Gansu)

机构地区：[1]中国科学院西北生态环境资源研究院,干旱区生态安全与可持续发展重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049 [3]西北师范大学地理与环境科学学院,甘肃兰州730000 [4]兰州大学地质科学与矿产资源学院,甘肃兰州730000

出　　处：《第四纪研究》2024年第6期1482-1494,共13页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:42202029和42271176);国家自然科学基金国际(地区)合作与交流项目(批准号:42161144012);科技部第二次青藏高原综合科学考察研究项目(批准号:2019QZKK0707);中国科学院“西部之光-西部交叉团队”重点实验室专项项目(批准号:xbzg-zdsys-202204);甘肃省自然科学基金项目(批准号:24JRRA087)共同资助。

摘　　要：单籽豆属(Podocarpium)是已经灭绝的一类豆科植物,也是新生代地层中广泛出现的类群。该属在欧亚大陆中有着丰富的化石记录,但由于缺乏重点区域以及关键时间点的化石证据,限制了对其演化与分布历史的认识。本研究以青藏高原东北部柴达木盆地瑙格剖面2100 m处的中新世地层中的单籽豆属为研究对象,结合新生代以来的全球化石记录,综合概述了该属的生物地理历史,并依据青藏高原地区的具有准确年代控制的化石记录探讨了环境变化对单籽豆属演变的影响。研究结果表明:1)依据柴达木盆地中中新世晚期新标本枝叶和荚果的形态比较,将其定为柄豆荚(Podocarpium podocarpum);2)依据已知的青藏高原化石记录表明,单籽豆属在中新世时期的分异度最高且分布特征与全球具有同步性,同时支持了该属通过低纬度路径扩散和传播的可能性;3)全球范围内的干旱和降温可能不是导致单籽豆属分布区范围缩小的主要原因,中新世之后青藏高原部分地区的地形进一步抬升通过改变降水模式促进了该属在亚洲内陆地区分范围的收缩。Podocarpium is an extinct genus of the family Fabaceae that was widely distributed in the Eurasian continent during Cenozoic.But the lack of fossil evidence from key regions and critical time points limits the understanding of its evolutionary and distributional history.In this study,we focus on the Middle Miocene Podocarpium of the Naoge section in the Qaidam Basin,located in the northeastern of the Tibetan Plateau.By integrating global fossil records from the Cenozoic,this paper provides a comprehensive overview of the biogeographical history of the genus and discusses how environmental changes influenced its evolution,based on accurately dated specimens from the Tibetan Plateau.The Naoge section is located about 43 km south of Gahai Town,Delingha City,in the northeastern of the Qaidam Basin,with a thickness of approximately 3300 meters.Exposed are the Upper Cretaceous Quanyagou Formation,the Miocene to Pliocene Lower Youshashan Formation,Upper Youshashan Formation,and the Shizigou Formation.The fossil specimens in this study were collected from the Upper Youshashan Formation of the section,at an elevation of 2100 meters,within greenish-gray muddy siltstone.According to paleomagnetic dating,the geological age of the fossil layer is approximately 11 Ma.Our results show that the well-preserved fossil fruits and leaves of the Podocarpium podocarpum were described from the Middle Miocene of the Qaidam Basin,northeast Tibetan Plateau.Furthermore,fossil records from the Tibetan Plateau indicate that the genus had its highest diversity during the Miocene,with a distribution pattern synchronous with global trends,supporting the possibility that the Podocarpium spread and dispersed via low-latitude routes.Thus,global aridification and cooling are unlikely to be the primary causes of the range contraction of the Podocarpium.Instead,further uplift of certain areas of the Tibetan Plateau after the Miocene,by altering precipitation patterns,which may have contributed to the reduction of the Podocarpium's distribution in inl

关 键 词：中新世 单籽豆属 生物地理学 柴达木盆地 

分 类 号：P534.621[天文地球—古生物学与地层学] Q949.751.9[天文地球—地质学]