 "R. brodiei" was first described and named by Michael Benton in 1990, but its redescription by Martín D. Ezcurra, Felipe Montefeltro and Richard J. Butler in 2016 recovered it as more closely related to the more advance hyperodapedontine than to the type species of "Rhynchosaurus" and thus it was moved to its own genus.The generic name "Langeronyx" honors the Brazilian paleontologist Max Cardoso Langer in recognition of his rhynchosaur research, combined with the Greek "onyx" ("óνυξ") meaning "claw", a common suffix for rhynchosaur genera."L.