Perleidus sinensis n. sp., a new species of "Subholostea " fossil fish of the order Perleidiformes is described herein on the basis of a single, well-preserved specimen collected from the Upper Member of the Guanling Formation (Pelsonian, Middle Anisian, Middle Triassic) outcropping near Luoping (Yunnan Province) in South China. The vertebrate assemblage yielded by these levels is proving to be of importance with regard to the marine Triassic ichthyofaunas, not only due to the variety, richness and quality of preservation of the faunas, but also from a paleobiogeographic point of view. The new taxon here described belongs to the genus Perleidus, so far represented only in the upper Ladinian of Northern Italy and Switzerland; this find reconfirms a very close connection between the Eastern and Western Tethys during the Middle Triassic, when many fish genera may have migrated from the Southern China Block to the Western Tethys area, giving rise to a notable radiation during some intervals of the Triassic. Besides Perleidus, other actinopterygians are common to both margins of the Tethys, such as Sangiorgioichthys, Habroichthys, Placopleurus, Peltopleurus, Peltoperleidus, Marcopoloichthys, Colobodus, Luopingichthys as well as the cosmopolitan genera Saurichthys and Birgeria