Aglyptorhynchus venablesi was another specialised long-snouted teleost in the London Clay fish assemblage. The preserved rostrum was substantial and internally traversed by nutrient canals, indicating a living, vascularised extension of the skull. Its overall construction suggests an active marine predator, but the exact feeding function of the bill remains an inference because the species is known mainly from isolated rostral material.

A. venablesi is especially informative for the diversity of bill-bearing fishes in the early Eocene. The rostrum changes markedly in section from its base toward the tip and its canal system simplifies distally, features that provide anatomical evidence for how the bill was constructed and reinforced.