A new genus of galeaspids(jawless stem-Gnathostomata)from the early Silurian Chongqing Lagerstätte,China  

重庆特异埋藏化石库盔甲鱼类一新属

作　　者：CHEN Yang LI Qiang ZHOU Zheng-Da SHAN Xian-Ren ZHU You-An WANG Qian WEI Guang-Biao ZHU Min 陈阳;李强;周政达;山显任;朱幼安;王倩;魏光飚;朱敏(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;重庆地质矿产研究院,重大地质事件资源环境效应重庆市重点实验室,重庆401120;中国科学院大学,北京100049;曲靖师范学院自然历史文化研究中心,云南曲靖655011;重庆市地质调查院,重庆401122)

机构地区：[1]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 [2]Chongqing Key Laboratory of Resources and Environment Effects of Major Geological Events,Chongqing Institute of Geology and Mineral Resource,Chongqing 401120 [3]University of Chinese Academy of Sciences,Beijing 100049 [4]Research Center of Natural History and Culture,Qujing Normal University Qujing,Yunnan 655011 [5]Chongqing Institute of Geological Survey,Chongqing 401122

出　　处：《古脊椎动物学报（中英文）》2024年第4期245-261,共17页Vertebrata Palasiatica

基　　金：国家自然科学基金(批准号:42002015);重庆市技术创新与应用发展专项重点项目(编号:CSTB2023TIAD-KPX0098);重庆市科研机构绩效激励引导专项(编号:cstc2022jxjl00008);重庆市规划和自然资源局古生物化石等地质遗迹保护与研究专项和重庆地质矿产研究院科研平台开放课题(编号:CKLEMME-202201)资助。

摘　　要：The early Silurian Chongqing Lagerstätte(middle Telychian)yields exceptionally preserved articulated jawless and jawed fishes.Here,we describe a new eugaleaspiform(Galeaspida,jawless stem-Gnathostomata),Miaojiaaspis dichotomus gen.et sp.nov.,from the Chongqing Lagerstätte in Xiushan,Chongqing,China.The new form resembles Tujiaaspis vividus in the short medial dorsal canal,and the presence of the branching ends of the lateral transverse canal.They differ in that T.vividus has highly developed subordinate branches of the sensory canals that form a reticulate sensory canal system,and the median dorsal opening is more elongated.Our phylogenetic analysis recovers M.dichotomus and T.vividus as a monophyletic clade(Tujiaaspidae fam.nov.),which is supported by two synapomorphies:the short medial dorsal canal,and the branching ends of the lateral transverse canal.Tujiaaspidae forms a trichotomy with Shuyuidae and a clade comprising Anjiaspis,Sinogaleaspidae,Yongdongaspidae,and the‘eugaleaspid cluster’.The sensory canal patterns in galeaspids are compared to show the transformation sequence of the sensory canal system in Eugaleaspiformes.志留纪(特列奇期)重庆特异埋藏化石库产出了大量完整保存的无颌类和有颌鱼类化石。描述了采自重庆秀山的真盔甲鱼目一新属种——双叉苗家鱼(Miaojiaaspis dichotomus gen.et sp.nov.)。新属种具有与灵动土家鱼(Tujiaaspis vividus)相似的特征,包括短的中背管和分叉的侧横管。二者的区别是:灵动土家鱼的侧线系统极度发育,形成了网状的感觉管,且具有更长的中背孔。系统发育分析结果显示,苗家鱼与土家鱼共同组成一个单系类群--土家鱼科(新科)。该新科具有两个共有衍征:短的中背管,以及侧横管末端分叉。隶属真盔甲鱼目的土家鱼科、曙鱼科以及一个包含了安吉鱼属、中华盔甲鱼科、涌洞鱼科和“真盔甲鱼簇”的支系构成了一个三分支。对盔甲鱼类的侧线系统进行了比较,并讨论了真盔甲鱼目侧线系统的特征演化序列。

关 键 词：Chongqing Lagerstätte TELYCHIAN Galeaspida MORPHOLOGY PHYLOGENY 

分 类 号：Q915.861[天文地球—古生物学与地层学]