Aulopopsis egertoni was a predatory aulopiform in the early Eocene London Clay sea. Its strong lower-jaw teeth indicate a grasping dentition suited to seizing fishes or other mobile prey, while radiating sculpture across the skull roof gives the head a strongly textured appearance. The preserved orbital region is comparatively lightly ossified rather than dominated by a heavy bony eye ring.

The species is represented mainly by three-dimensional cranial fossils. This preservation provides good information on skull architecture and feeding anatomy while leaving the full body form less certain. Its robust dentition and elongate predatory head support an active carnivorous lifestyle, with exact prey inferred from anatomy rather than directly preserved.