biostudies-literatureUnknown12Li QNew discoveries of the late Silurian fossil fish <i>Dunyu</i> (Eugaleaspidae, Eugaleaspiformes, Galeaspida), <i>Dunyu tianlu</i> sp. nov. and <i>Dunyu</i> sp., are described from the Xiaoxi Formation in Xiushan of Chongqing and Xiushui of Jiangxi, China respectively. <i>D. tianlu</i> sp. nov. can be distinguished from <i>D. longiforus</i> and <i>D. xiushanensis</i> in its nearly equal preorbital and postorbital regions of the headshield. As the currently only known genus of Eugaleaspiformes during the late Silurian, <i>Dunyu</i> not only displays a large morphological difference with galeaspids from both the early Silurian and Early Devonian but also occupies a phylogenetic position that is far from the root of Eugaleaspiformes, which indicates that the lineages nested between YongdongaspiPeerJe18760https://www.ebi.ac.uk/biostudies/studies/S-EPMC11674142biostudies-literatureNew findings of <i>Dunyu</i> (Eugaleaspiformes, Galeaspida) from the Xiaoxi Formation in South China and their biostratigraphic significance.PMC11674142Zheng JZhu MShan XZhao WLin XLi QChen YPeng LGai ZfalseNew findings of <i>Dunyu</i> (Eugaleaspiformes, Galeaspida) from the Xiaoxi Formation in South China and their biostratigraphic significance.New discoveries of the late Silurian fossil fish <i>Dunyu</i> (Eugaleaspidae, Eugaleaspiformes, Galeaspida), <i>Dunyu tianlu</i> sp. nov. and <i>Dunyu</i> sp., are described from the Xiaoxi Formation in Xiushan of Chongqing and Xiushui of Jiangxi, China respectively. <i>D. tianlu</i> sp. nov. can be distinguished from <i>D. longiforus</i> and <i>D. xiushanensis</i> in its nearly equal preorbital and postorbital regions of the headshield. As the currently only known genus of Eugaleaspiformes during the late Silurian, <i>Dunyu</i> not only displays a large morphological difference with galeaspids from both the early Silurian and Early Devonian but also occupies a phylogenetic position that is far from the root of Eugaleaspiformes, which indicates that the lineages nested between Yongdongaspi2024-01-01T00:00:00Z20242025-04-19T21:31:12.953Z2025-04-19T21:31:12.953ZS-EPMC116741423973555710.7717/peerj.18760