A basal antiarch (placoderm fish) from the Silurian of Qujing, Yunnan, China

A new basal antiarch, Silurolepis platydorsalis n. gen. n. sp., represented by a large-sized trunk armor and a disassociated anterior median dorsal plate (AMD), is described from the Ludlow (Silurian) of Qujing, Yunnan, southwestern China. It is characterized by its AMD overlapping the posterior median dorsal plate, broad anterior margin of the AMD, and crest-shaped dorsolateral ridge of the trunk armor. As the oldest known articulated placoderm fish to date, the new fish provides new insights into the early evolution of antiarchs.