The previously alleged ‘semionotid’ fish Asialepidotus shingyiensis from the Middle Triassic (Ladinian) marine deposits of Guizhou and Yunnan, China has recently been identified as a halecomorph, but its phylogenetic relationships with other halecomorphs remain controversial. This taxon was successively placed in different halecomorph orders: Amiiformes, Parasemionotiformes and ‘Panxianichthyiformes’. Here, a detailed redescription of Asialepidotus is presented based upon a comparative study of the original material with 50 new specimens. Newly recognized anatomical information includes a V-shaped rostral, paired vomers, a toothed parasphenoid, a dermosphenotic with a canal-bearing innerorbital flange, a splint-like quadratojugal, a branch of the infraorbital sensory canal in the maxilla, and many elements in the hyoid and branchial apparatuses and the lower jaw. Results of a cladistic analysis incorporating these new data indicate that the ‘Panxianichthyiformes’ is a poorly defined, paraphylectic grade; Asialepidotus is not sister to Panxianichthys as previously suggested; instead, it is more derived than Panxianichthys and consists of the sister taxon of the clade Robustichthys plus Jurassic–Cretaceous ionoscopiforms. This phylogenetic reassessment of Asialepidotus extends the stratigraphic range of the Ionoscopiformes in China by ~4 Myr and supports the hypothesis that the early ionoscopiform diversification was already established by the Middle Triassic.