Lashanichthys sui

Lashanichthys sui is a small fusiform neopterygian ray-finned fish from the Middle Triassic (Anisian, ~244 Ma) of Luoping, Yunnan, China. Adults are generally about 10 cm in total length with a glossy ganoid scale cover, a slightly raised back with prominent ridge scutes, a small mouth cleft, pointed teeth on the upper and lower jaws, numerous postorbital bones, an operculum distinctly larger than the subopercle, and small fins. The species was originally described as Sangiorgioichthys sui, compared with the two species of Sangiorgioichthys from the Monte San Giorgio fauna on the Swiss-Italian border. A 2019 restudy of the Anisian kyphosichthyiform Yudaiichthys eximius and early ginglymodian relationships recovered Sangiorgioichthys sui together with its congener as a separate lineage, for which the new genus Lashanichthys was erected within the new family Lashanichthyidae alongside Yudaiichthys, while Sangiorgioichthys proper was removed from the Kyphosichthyiformes. Lashanichthys sui is the most abundant neopterygian fish of the Luoping Biota and is interpreted as a gregarious, small-bodied swimmer feeding in the shallow Anisian sea.