[PaleoIchthyology • 2023] Jiangxialepis rongi • The First Eugaleaspiforme Fish from the Silurian of the Tarim Basin reveals a close relationship between the Tarim and South China Blocks at 438 mya

Xiyuichthys zhangi [Xiushuiaspidae], Microphymaspis pani [Dayongaspidae], Platylomaspis serratus [Gumuaspidae], and
 Jiangxialepis rongi [Shuyuidae]  Liu, Shan, Lin, Shen, Liu, Zhang & Gai, 2023

DOI: doi.org/10.1016/j.palaeo.2023.111774

 

Highlights: 

• The first Eugaleaspiforme fish, Jiangxialepis rongi sp. nov., is established.

• The Tataertag Formation can be correlated with the Qingshui Formation.

• Shuyuidae provided key evidence for the correlation of Silurian LRBs in China.

• 5 dispersal events between South China and Tarim blocks were recognized.

• South China and Tarim blocks should be closely related at 438 mya.

Abstract

The first Eugaleaspiforme fish, Jiangxialepis rongi sp. nov., from the lower Telychian (Llandovery, Silurian) Tataertag Formation in the Tarim Basin is described and its palaeogeographic significance is evaluated. The new species can be assigned to the family Shuyuidae and distinguished from J. retrospina and J. jiujiangensis by its comparatively broader headshield, ornamentation, and serrated margin of the headshield and median dorsal opening. The discovery of J. rongi provides direct fossil evidence for the correlation of lower Telychian marine red beds between the Tarim Basin and South China and expands our knowledge of the distribution of Eugaleaspiforme fish into the Tarim Basin. An analysis of galeaspid paleogeographic distribution within a phylogenetic framework reveals at least five galeaspid dispersal events between the blocks of South China and the Tarim Basin during the early Telychian age. This indicates that the South China and Tarim blocks were close enough to share the same shallow marine environment, and perhaps comprise a united Tarim-South China Block during the early Silurian.

  

Keywords: Silurian, Galeaspid, Tarim, South China, Biogeography

Xiyuichthys zhangi [Xiushuiaspidae], Microphymaspis pani [Dayongaspidae], Platylomaspis serratus [Gumuaspidae], and Jiangxialepis rongi [Shuyuidae] 

 Jiangxialepis rongi sp. nov.

 

Wenyu Liu, Xianren Shan, Xianghong Lin, Yiming Shen, Yuhang Liu, Zehao Zhang and Zhikun Gai. 2023. The First Eugaleaspiforme Fish from the Silurian of the Tarim Basin reveals a close relationship between the Tarim and South China Blocks at 438 mya. Palaeogeography, Palaeoclimatology, Palaeoecology. 628; 111774. DOI: doi.org/10.1016/j.palaeo.2023.111774