Campyloxenus is a bioluminescent genus of click beetles in the family Elateridae, and had been the sole member of the subfamily Campyloxeninae, until another monotypic genus ' was described from Chile in 2015 as its new member. There is one described species in Campyloxenus, Campyloxenus pyrothorax, from southwestern Chile and Argentina.
Black with a reddish pronotum. long, dense, bristly and brownish. Eyes very small. Front . Antennae elongate, surpassing the hind angles of the prothorax, from the fourth segment onwards; second segment short, third elongate, two times longer than second and of the same length as the fourth. Prothorax subquadrate, slightly convex. Luminous spots occupying the entire middle region on each side of the prothorax and visible beneath on the . cavity almost horizontal. plate very narrow and of the same width throughout. Abdominal luminous organ absent. Male genitalia: median lobe narrow and straight; lateral lobes elongate, with few hairs. Female genitalia: stylus and baculum elongate, eighth elongate inwardly; not spiraled, with a few scales. Sexual dimorphism accentuated; females with small eyes, more convex and more rounded prothorax; antennae shorter.