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古脊椎动物学报 ›› 2021, Vol. 59 ›› Issue (4): 257-272.DOI: 10.19615/j.cnki.2096-9899.210727

• •    下一篇

云南曲靖下泥盆统最大真盔甲鱼类漫游憨鱼再描述

孟馨媛1,3, 朱敏1,2,3, 盖志琨1,2,3,*()   

  1. 1 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
    2 中国科学院生物演化与环境卓越创新中心 北京 100044
    3 中国科学院大学 北京 100049
  • 收稿日期:2021-06-02 出版日期:2021-09-20 发布日期:2021-10-18
  • 通讯作者: * gaizhikun@ivpp.ac.cn
  • 基金资助:
    国家自然科学基金(41972006);国家自然科学基金(42072026);中国科学院前沿科学重点研究计划(QYZDB-SSW-DQC040);国家高层次人才特殊支持计划(万人计划)和中国科学院战略性先导科技专项资助(XDB26000000)

Redescription of Nochelaspis maeandrine ,the largest eugaleaspiform from the Lower Devonian of Qujing, Yunnan

MENG Xin-Yuan1,3, ZHU Min1,2,3, GAI Zhi-Kun1,2,3,*()   

  1. 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 CAS Center for Excellence in Life and Paleoenvironment Beijing 100044
    3 University of Chinese Academy of Sciences Beijing 100049
  • Received:2021-06-02 Published:2021-09-20 Online:2021-10-18

摘要:

基于在云南曲靖西山村组两个不同产地发现的新材料,对最大的真盔甲鱼类漫游憨鱼(Nochelaspis maeandrine )进行了再描述。憨鱼属(Nochelaspis )与同一层位产出的云南盔甲鱼属(Yunnanogaleaspis )最为相似,但与后者明显不同的是,憨鱼属具有裂隙形的中背孔(长与宽之比大于6), 更强壮的内角,粗大的星状纹饰,以及具锯齿的中背孔和头甲边缘。漫游憨鱼的新材料提供了头甲腹面的关键形态学信息:口鳃窗被一个大的外骨骼腹片覆盖,该腹片上装饰着致密细小的瘤点,边缘排列有6对独立的圆形大鳃孔,这些鳃孔由腹片和腹环共同形成。盔甲鱼类的这种情况明显不同于骨甲鱼类,后者的口鳃窗被许多小嵌片或大一些的膜质小骨片覆盖,鳃孔呈裂隙状,并被小皮瓣覆盖,类似于现生的板鳃类。盔甲鱼类和骨甲鱼类的鳃孔与现生的鳐类一样,都开口于腹面,指示它们均为底栖鱼类,生活在具泥沙质基底的安静滨海环境中。

关键词: 云南曲靖, 早泥盆世, 真盔甲鱼类, 憨鱼属

Abstract:

The new specimens of the largest eugaleaspiform Nochelaspis maeandrine are redescribed from two localities of the Xishancun Formation in Qujing City, Yunnan Province, southwestern China. Nochelaspis is most suggestive of Yunnanogaleaspis from the same horizon, but differs in its slit-like median dorsal opening (length/width>6), much stronger inner cornual process, coarse stellate ornamentation, and the serrations along the edges of the median dorsal opening and headshield. The new findings reveal the morphological details on the ventral side of the headshield as well. The oralobranchial fenestra is covered by a large dermal ventral plate, which is decorated with dense, tiny granular tubercles, and aligned with six pairs of separated, large, and circular branchial openings. This condition is different from that of osteostracans, in which the oralobranchial fenestra is covered by numerous minute scales or larger dermal platelets, and the branchial openings are slit-shaped and covered by small skin flaps somewhat like those of elasmobranchs. However, the branchial openings of galeaspids and osteostracans are both located ventrally as in modern rays, indicating a benthic lifestyle dwelling on sandy or muddy substrates in a quiet marine environment.

Key words: Qujing, Yunnan, Early Devonian, eugaleaspiform, Nochelaspis

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