辽西侏罗纪紫萁科植物根茎化石解剖构造及发育演化

The family Osmundaceae receives much concern of palaeobotanists for its extensive fossil records and special phylogenetic relationships. Permineralized rhizomes, with abundant anatomical and phylogenetic information, play a prominent role in understanding the classification and phylogeny of the Osmundaceae. The geographic and geological distribution of the osmundaceous rhizome fossil is quite uneven; most of these fossils are recorded in the Southern Hemisphere. The western Liaoning region is one of the most important Jurassic fossil localities for permineralized osmundaceous rhizomes in the Northern Hemisphere. Therefore, this region is with peculiar significance in both locality and horizon. This research project aims to investigate the systematic palaeontology of the osmundaceous rhizome fossils collected from the Middle Jurassic Tiaojishan Formation of western Liaoning Province. On this base, the phylogeny of the Osmundaceae will be discussed by utilizing the cladistic analysis. Additionally, an overview on fossil osmundaceous ferns from China is given based on analysis of available fossil records of leaf and rhizome remains. The fossil diversity variation, as well as the geological and geographical distribution pattern of osmundaceous plants in China is discussed, which will provide further evidence for understanding the macroevolution of the family Osmundaceae in China. The systematic investigations of these Chinese material help to improve the diversity of osmundaceous rhizome fossils in the Northern Hemisphere, and will contribute to better understand the radiation and evolution of Osmundaceae in the Mesozoic, as well as the origin of extant osmundaceous taxa.

紫萁科其因广泛的化石记录和特殊的系统发育位置而在真蕨植物中备受关注。紫萁科矿化根茎化石保存有丰富的解剖学及系统发育信息，在该科化石植物的分类学及系统发育研究中占据主导地位。紫萁根茎化石在全球分布不均，其产地多集中在南半球；中国辽西地区是北半球为数不多的侏罗纪紫萁科矿化根茎化石产地，其无论在产地及时代上都具有重要研究意义。本课题拟以中国辽西地区中侏罗统髫髻山组紫萁科矿化茎干化石为研究对象，对其开展系统古生物学研究，结合分支分析方法探究紫萁科的系统发育特征；在此基础上，结合中国保存丰富的紫萁科叶部化石记录对中国紫萁科植物化石的属种多样性及其时空分布规律进行研究，以揭示该科植物在中国的宏演化特征。该研究有助于丰富北半球紫萁科根茎化石的属种多样性，并为揭示紫萁科植物的系统发育、中生代辐射演化过程及其现生类群的起源提供化石证据。

对辽西地区中-上侏罗统髫髻山组紫萁科矿化茎干化石及伴生的解剖构造保存完好的木化石开展野外调查和室内综合研究。本项目在紫萁科矿化根茎解剖学及系统古生物学、中国化石紫萁目植物多样性、时空分布特征及演化特征、辽西中生代木化石新材料及其古气候指示意义等方面取得了积极进展。主要包括：1）报道了产自辽西侏罗纪髫髻山组的两种解剖特征保存完好的紫萁科矿化茎干化石新类型，即：王氏阿氏茎（Ashicaulis wangii sp. nov.）和似普拉姆阿氏茎（Ashicaulis plumites sp. nov.），丰富了北半球紫萁根茎化石的多样性；分析二者与现生生紫萁属紫萁亚属（subg. Osmunda）的某些类群的亲缘关系。2）系统总结中国紫萁目植物化石记录、多样性演变以及地质和地理分布特征，揭示了紫萁目植物在我国的起源和发展演化过程及其环境指示意义。3）首次报道了产自辽西建昌侏罗纪髫髻山组解剖构造保存完好的木化石新材料，提出辽西地区在侏罗纪时期是异木属（Xenoxylon Gothan）重要的辐射演化中心，利用树木年轮法分析了髫髻山组沉积时期的古气候特征。4）报道了产自辽西北票下白垩统义县组及义县下白垩统九佛堂组的木化石新材料，进一步丰富了对热河植物群森林植被群落组成特征的认识。先后参与国内外学术会议10余次，提交中英文会议摘要10余篇，做中英文口头报告8次。共发表学术论文10余篇，其中第一作者或通讯作者SCI 论文 6篇，中文核心期刊论文2 篇，科普论文1 篇。入选2015年度“辽宁省百千万人才工程”万人层次人选。项目组成员1人博士毕业，1人考取博士研究生。