Donald E. Hurlbert, Smithsonian Institution
Aquatic plant eaters, like these marine iguanas, have evolved shorter and deeper skulls with strong jaws and teeth for crushing their food. Smithsonian scientist Neil Kelly used a novel, quantitative approach to compare dietary data of living marine species with measurements of their skulls and teeth and found that distantly related animals with shared diets evolved similar adaptations to successfully live in the sea. (Photo by Donald E. Hurlbert, Smithsonian Institution)
