Aetobatus irregularis was an eagle ray, part of a group of broad-winged rays adapted for powerful swimming above the seafloor. Like living eagle rays, it was probably an active benthopelagic animal that moved through coastal and shelf waters while foraging on the bottom.

Its broad crushing teeth formed a pavement capable of breaking hard-shelled prey. Molluscs and crustaceans are therefore likely components of its diet, although the exact prey species cannot be demonstrated from isolated dental material alone.

Most fossils of A. irregularis are individual teeth or fragments of the dental pavement rather than complete skeletons. These remains nevertheless show a clear feeding specialisation: instead of using pointed teeth to seize prey, the ray processed resistant food with a broad crushing surface.