滇东曲靖地区早泥盆世真盔甲鱼科一新属种  

Xitunaspis, a new eugaleaspid fish (Eugaleaspiformes, Galeaspida) from the Lower Devonian of Qujing, Yunnan

作　　者：孙浩然 盖志琨[2,3,4] 蔡家琛 李强 朱敏 赵文金[2,3,4] SUN Hao-Ran;GAI Zhi-Kun;CAI Jia-Chen;LI Qiang;ZHU Min;ZHAO Wen-Jin(Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029;Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences,Institute of Vertebrate Paleontology and Paleoanthropology,Chinese Academy of Sciences,Beijing 100044;University of Chinese Academy of Sciences,Beijing 100049;CAS Center for Excellence in Life and Paleoenvironment,Beijing 100044;Research Center of Natural History and Culture,Qujing Normal University Qujing,Yunnan 655099)

机构地区：[1]中国科学院地质与地球物理研究所,北京100029 [2]中国科学院古脊椎动物与古人类研究所,中国科学院脊椎动物演化与人类起源重点实验室,北京100044 [3]中国科学院大学,北京100049 [4]中国科学院生物演化与环境卓越创新中心,北京100044 [5]曲靖师范学院自然历史文化研究中心,云南曲靖655099

出　　处：《古脊椎动物学报（中英文）》2022年第3期169-183,共15页Vertebrata Palasiatica

基　　金：中国科学院战略性先导科技专项(编号:XDB26000000);国家自然科学基金(批准号:41972006,42072026);中国科学院前沿科学重点研究计划(编号:QYZDB-SSW-DQC040);国家高层次人才特殊支持计划(万人计划)资助。

摘　　要：记述了采自云南曲靖下泥盆统西屯组中的真盔甲鱼科一新属种--硕大西屯鱼(Xitunaspis magnus gen.et sp.nov.)。新属具有真盔甲鱼科的典型特征,包括一个纵长裂隙状的中背孔、没有内角、发达的中背管以及只有3对从侧背管上伸出的侧横管等,但其具有大而厚的头甲以及更原始的感觉管系统等特征明显区别于其他真盔甲鱼类。系统发育分析表明,西屯鱼属(Xitunaspis)与盾鱼属(Dunyu)和真盔甲鱼属(Eugaleaspis)共同组成一个单系类群--真盔甲鱼科支系(Eugaleaspidae Liu,1965),并且三者之间西屯鱼与盾鱼的亲缘关系更为密切。作为曲靖地区下泥盆统西屯组中确凿的真盔甲鱼类化石记录,西屯鱼的发现加深了对真盔甲鱼类形态学及真盔甲鱼目乃至盔甲鱼亚纲中感觉管系统演化的认知。A new genus and species of the family Eugaleaspidae(Eugaleaspiformes,Galeaspida),Xitunaspis magnus gen.et sp.nov.,is described from the Lower Devonian Xitun Formation in Qujing,Yunnan Province,China.The new genus displays the diagnostic characters of the Eugaleaspidae,including a slit-like median dorsal opening,no inner cornual process,developed median dorsal canals,and only three pairs of lateral transverse canals extending from lateral dorsal canals.Different from the other eugaleaspids,X.magnus possesses a large headshield with thick dermal bone and a more plesiomorphic sensory canal system.The phylogenetic analysis of the Galeaspida reveals that Xitunaspis clusters with Dunyu and Eugaleaspis to form a monophyletic clade Eugaleaspidae Liu,1965,and has a closer relationship with Dunyu than Eugaleaspis by sharing the thick dermal bone of the headshield.The new finding represents the first convincing fossil record of the Eugaleaspiformes in the middle Lochkovian Xitun Formation and adds to our knowledge about the morphology of eugaleaspiforms and the evolutionary pattern of the sensory canal system in the Eugaleaspiformes and even Galeaspida.

关 键 词：云南曲靖 早泥盆世 真盔甲鱼类 西屯鱼 感觉管系统 

分 类 号：Q915.861[天文地球—古生物学与地层学]