欢迎访问《古脊椎动物学报》官方网站,今天是

古脊椎动物学报

• •    

湖南二叠纪乐平世棘鳞鲨Listracanthus (软骨鱼类)的发现

房庚雨1,2   牟  林3   季  承3   李  航4   杨  涛4   杨  爽4,5   杨晨光3   吴飞翔4   

  1. (1 英国布里斯托大学地球科学学院  布里斯托BS8 1TQ)
    (2 英国伦敦自然历史博物馆地球科学部  伦敦 SW7 5BD)
    (3 中国科学院南京地质古生物研究所,古生物学与油气地层应用全国重点实验室  南京 210008)
    (4 中国科学院古脊椎动物与古人类研究所  北京100044)
    (5 中国科学院大学地球与行星科学学院  北京 100049)

Enigmatic Listracanthus (Chondrichthyes, incertae sedis) from the Lopingian (Permian) of Hunan Province, China

FANG Geng-Yu1,2   MU Lin3   JI Cheng  LI Hang4   YANG Tao4   YANG Shuang4,5   YANG Chen-Guang3   WU Fei-Xiang4*   

  1. (1 School of Earth Sciences, University of Bristol Bristol BS8 1TQ, UK)
    (2 Department of Earth Sciences, Natural History Museum London SW7 5BD, UK)
    (3 State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing 210008, China)
    (4 Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences Beijing 100044, China)
    (5 College of Earth and Planetary Sciences, University of Chinese Academy of Sciences Beijing 100049, China)
    *  Corresponding author: wufeixiang@ivpp.ac.cn

摘要:

二叠–三叠纪大灭绝(PTME)是显生宙最严重的生物危机事件,对水生脊椎动物的演化产生了深远影响。然而,二叠纪晚期化石记录的稀缺限制了我们对该事件生物学效应的进一步研究。报道了产于湖南湘中地区的邵阳动物群,生物地层学证据表明其时代为二叠纪乐平世吴家坪期晚期,约早于PTME 5 myr。邵阳动物群中包含神秘的棘鳞鲨类(Listracanthidae), 它被认为是某种未知软骨鱼的皮齿(dermal denticles), 常见于晚古生代的海相地层。新发现的材料在形态上与早三叠世的棘鳞鲨类十分相似,后者也是该类群已知最晚的化石记录。新材料前缘棘刺的特征支持建立一新种:邵阳棘鳞鲨(Listracanthus shaoyangensis sp. nov.)。此外,化石表面的微区X射线荧光(micro-XRF)成像显示,邵阳产地深色和浅色的围岩具有不同的元素分布,这可能受到了后埋藏改造过程的影响。连同共存的硬骨鱼化石(如龙鱼类), 邵阳动物群提供了PTME前海洋生态系统的记录,同时也让我们对中生代海洋革命(Mesozoic Marine Revolution)之前的鱼类面貌有了更多了解。

关键词: 软骨鱼类, 棘鳞鲨类, 二叠–三叠纪大灭绝, 微区X射线荧光成像, 古生物地理学

Abstract:

The Permo–Triassic mass extinction (PTME) was the most severe biotic crisis of the Phanerozoic and had profound effects on aquatic vertebrates. However, the sparse vertebrate fossil record of the late epoch of Permian has limited further assessment of the ecological impact of the crisis. This study reports the Shaoyang Fauna from central Hunan Province, South China, for which biostratigraphic evidence indicates a late Wuchiapingian age, approximately 5 million years before the PTME. The Shaoyang Fauna includes listracanthids, an enigmatic group represented by chondrichthyan dermal denticles and commonly found in Late Paleozoic marine strata. The new material closely resembles the Early Triassic listracanthids, which are the youngest known record of the group. However, differences in the anterior fulcra justify the establishment of a new species, Listracanthus shaoyangensis sp. nov. We also used micro-X-ray fluorescence (micro-XRF) imaging to investigate elemental distributions on the fossil surfaces and found that specimens of different colors show distinct preservation modes. Together with co-existing osteichthyan fossils (e.g., saurichthyiform fishes), the Shaoyang Fauna provides a snapshot of a marine ecosystem shortly before the PTME and offers new insight into fish diversity prior to the Mesozoic Marine Revolution.

Key words: Listracanthus, Chondrichthyes, PTME, XRF, paleobiogeography