Analysis of information sources in references of the Wikipedia article "Passalidae" in Portuguese language version.
All species of Ogyges are flightless, presenting reduced hindwings, rounded and fused elytra, and reduced eyes, four characters shared with other mountain living genera of Passalidae (e.g., Xylopassaloides Reyes-Castillo, Fonseca, & Castillo, Proculus Kaup, Proculejus, Undulifer Kaup, and Pseudacanthus Kaup).
The sound of the beetle from Passalidae family (vídeo).