The discovery of a large ceratodontiform lungfish from the Middle Triassic (Anisian) of Shanxi, China

doi:10.19615/j.cnki.2096-9899.251111

Abstract

Abstract:

Ceratodontiformes is the only extant order of Dipnoi (lungfishes). Fossil remains of this group are rare in Triassic deposits in China. Here, we report the recent discovery of a large ceratodontiform lungfish from the Anisian (Middle Triassic) Sinokannemeyeria Fauna in the Taigu District of Jinzhong City, Shanxi Province, China. The specimen was preserved in the argillaceous siltstones from the Third (uppermost) Member of the Ermaying Formation, including remains of 20 caudal vertebrae and associated elements (‘supraneurals’, interhaemals and dorsal and ventral radials) as well as a series of dorsal fin rays. The discovery documents the oldest articulated ceratodontiform in East Asia, predating the previously known articulated ceratodontiform from the Early Jurassic Yuzhou Biota by at least 43 Ma. With an estimated length of ~162 cm, it represents the largest articulated ceratodontiform known so far in the Triassic. The new finding adds to our knowledge regarding body size, morphological diversity, and the paleogeographic distribution of early ceratodontiforms.

Key words: Jinzhong, Shanxi, Middle Triassic, Ceratodontiformes, Sinokannemeyeria Fauna

摘要：

角齿鱼目是肺鱼超目中唯一包括现生成员的目级单元，其化石少见于中国三叠纪地层。最近在山西省中三叠世安尼期中国肯氏兽动物群发现一种大型角齿鱼目肺鱼。化石保存于晋中市太谷区二马营组第三段(最上段)的泥质粉砂岩中，包括20块尾椎骨及相关的 “上神经骨”, 间椎骨和背、腹辐鳍骨和一系列背鳍条。它代表了东亚已知最古老的、保持自然连接状态的角齿鱼目化石，比此前在早侏罗世渝州生物群发现的角齿鱼目化石至少早43 Ma。据估计，该肺鱼体长约为162 cm, 是迄今已知三叠纪最大的、自然连接状态的角齿鱼目化石。这一发现增加了对早期角齿鱼目体型大小、形态多样性和古地理分布的认识。

关键词: 山西晋中, 中三叠世, 角齿鱼目, 中国肯氏兽动物群

CLC Number:

Q915.862

SHI Jian-Ru, KANG Zhi-Shuai, DONG Li-Yang, JIA Gao-Wen, WANG Jin, JIA Lei, XU Guang-Hui. The discovery of a large ceratodontiform lungfish from the Middle Triassic (Anisian) of Shanxi, China. Vertebrata Palasiatica, 2026, 64(2): 183-190.

史建儒, 康志帅, 董黎阳, 贾高文, 王瑾, 贾磊, 徐光辉. 2026, 64(2): 183-190, 山西中三叠世安尼期一大型角齿鱼目肺鱼. 古脊椎动物学报.

Figures/Tables 2

Fig. 1 Fossil locality and stratigraphic section of the lungfish from the Middle Triassic (Anisian) of Jinzhong, Shanxi, China A. locality map; B. stratigraphic section. U-Pb geochronologic ages from Liu et al. (2018) Map approved number: GS(2019)3333

Fig. 2 Vertebral column with associated elements and fin rays of the ceratodontiform from the Middle Triassic of Shanxi Province and comparison with those of other ceratodontiforms A, B. photo (A) and line-drawing (B) of SXMG V2038; C. reconstruction of Paraceratodus germaini from the Lower Triassic of Madagascar (from Schultze, 2004) with a square indicating the area comparable to the specimen from Shanxi, China; D. skeleton and fins of extant Neoceratodus from Queensland (from Günther, 1871); E. caudal vertebra of extant Lepidosiren from South America (modified from Arratia et al., 2001) Abbreviations: bv. blood vessels; dra. dorsal radial; d.ry. dorsal fin ray; ha. haemal arch; hs. haemal spine; iha. interhaemal; na. neural arch; nc. spinal cord; no. notochord; ns., neural spine; ‘su’. ‘supraneural’; vra. ventral radial

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