A new tubalepid fish (Antiarcha, Placodermi) from the Middle Devonian of Huize, Yunnan, China

Abstract

A new genus and species of tubalepid antiarch, Tongdulepis concavus gen. et sp. nov., is described from the Middle Devonian (Qujing Formation, late Eifelian) in Huize County, Qujing, northeastern Yunnan, China. It differs from other antiarchs in the trapezoidal premedian plate, the absence of a postmarginal plate (except Tubalepis), trifid preorbital recess, contorted infraorbital sensory line on the lateral plate, and an anterior median dorsal plate with broad anterior margin and concave posterior margin. This material confirms the absence of the postmarginal plate in Tubalepididae and adds to the understanding of the neurocranium and brachial process in basal bothriolepidoids. Our phylogenetic result places Tongdulepis gen. nov. within Tubalepididae, specifically at the plesiomorphic position of the Tenizolepis-Dianolepis-Bothriolepis lineage.