An interesting new palaeoniscoid actinopterygian (Osteichthyes) from the Lower Permian of Southeastern Kazakhstan

Abstract

Khantausia tshuiliensis gen. et sp. nov. is described from the Lower Permian deposits of the Tshu-Ili Mountain region in Southeastern Kazakhstan. This taxon resembles the families Amblypteridae and Rhabdolepididae in general appearance, position and shape of fins, and scale structure. It differs from both these families in the structure of the opercular series of bones. The well-developed dorsal ridge scutes originating well behind the occiput is also a distinctive character of Khantausia. Several advanced characters, like the presence of patches of small irregular scales at the fin bases, the absence of laniary teeth, the bluntly rounded snout without distinct rostrum, and other skull characters in combination, support close relationships between Khantausia and Amblypteridae. However, this new genus differs in the absence of medial extrascapular, dermohyal, and perhaps spiracular, and in the presence of a single bone in the demosphenotic region. The new genus is believed to be a probable sistertaxon for amblypterids. It is supposed that a revision of the palaeoniscoid classification based mostly on the structure of the opercular series of bones is needed.