A new species of Sangiorgioichthys Tintori & Lombardo, 2007 (Actinopterygii; Semionotiformes) from the Pelsonian (Anisian, Middle Triassic) of Guizhou Province, South China

Sangiorgioichthys yangjuanensis sp. nov., from the Middle Triassic (Pelsonian, Middle Anisian) vertebrate fossiliferous layers of the upper Member of the Guanling Formation in the Dry Well Site, near Yangjuan Village, Panxian County, Guizhou Province, South China, is herein described. The presence of one single anterior infraorbital, a large infraorbital at the posteroventral corner of the orbit, one ventral suborbital covering the quadrate and quadratojugal, small dorsal fin limited to the area between the origin of the pelvic and anal fins supports the generic assignment of the new taxon. Of the known Sangiorgioichthys species, it closely resembles S. sui in having the median part of the supratemporal commissure lodged in the parietals, the presence of a sensory canal entering the posteriormost supraorbital, an elongated supramaxilla fitting in an excavation of the dorsal border of the maxilla, etc., which do not occur in S. aldae and S. valmarensis, although phylogenetic signal of these features are pending. The new taxon differs from S. sui in the number of dorsal suborbitals, the structure and row number of the scales, and also the dermosphenotic dorso-ventrally elongated, rectangular in shape, with the temporal canal entering the element at the dorsal half, then turning ventrally into the infraorbital canal rather than going posterior to the supraorbital canal.