A New Bothriolepid Antiarch from the Middle Devonian in Luquan, Yunnan, South China and Its Stratigraphic and Biogeographic Significances

Chahuaqingolepis magniporus gen. et sp. nov., a new taxon of Bothriolepididae (Placoder-mi: Antiarcha), is described from the Middle Devonian in Luquan County, Yunnan Province, South China. The phylogenetic analysis shows that Chahuaqingolepis is the sister group of Wufengshania with the synapomorphy of the large obtected nuchal area. Together with the findings of other associated antiarchs including Dianolepis, Bothriolepis, and Hunanolepis, the new bothriolepid antiarch is assigned to the Bothriolepis sinensis-Hunanolepis fish assemblage, which characterizes the Eifelian of the Middle Devonian in South China. The fish-bearing Tanglishu Formation can be well correlated with the Tiao-majian Formation in Changsha, Shangshuanghe Formation and lower part of the Haikou Formation in Qujing, and Laohutou Formation in Shaoguan and Lechang areas. This discovery not only enriches the Middle Devonian diversity of bothriolepids, but also provides reliable paleoichthyological evidence on the division and correlation of the fish-bearing Devonian strata in South China and deepens the understanding of the biogeography of the Devonian bothriolepids.