"Altirhinus" was one of a number of advanced iguanodontians with snouts expanded outwards towards the end. This is quite possibly an example of convergent evolution with hadrosaurids, famous for their wide "duckbill" snouts. These adaptations are also paralleled in many living mammalian herbivores of different lineages. Modern cows, horses, and white rhinoceros all exhibit wide muzzles and all are grazing animals. Grazing most often occurs at ground level, and if the expanded muzzles of "Altirhinus" and other related species were an adaptation to grazing, this may also explain corresponding weight-bearing adaptations of the forelimbs in derived iguanodontians, in order to get the head closer to the ground.