Differences in sharks’ olfactory systems are of interest not only because of their reputation for having an incredible sense of smell but also because they have been around since before the dinosaurs. They managed to thrive in every known marine habitat for millions of years — their sense of smell may have been key. A study is the first to quantify olfactory organ morphology by examining rosette shape and other internal structures among a diverse set of shark species using dissections, phylogenetic comparisons, and a fairly new technique, called diffusible iodine?based contrast-enhanced computed tomography imaging. Results reveal that the organs did not change in shape or number of lamellae throughout the life stages, suggesting that olfaction is a key sensory modality throughout the life of elasmobranch fishes.