The distinctive form of a winghead shark (Eusphyra blochii) is revealed by an X-ray image. The Winghead Shark, one of about ten species of hammerhead sharks, has its eyes set at the tips of its wide, T-shaped head, giving it superb binocular vision. Scientists in the Division of Fishes at the Smithsonian's National Museum of Natural History use X-ray images, like the one shown, to study the complex bone structure and diversity of fish without having to dissect or damage the specimen.
In 2012, the National Museum of Natural History hosted "X-Ray Vision: Fish Inside Out," a temporary exhibit that showcases fish evolution and diversity through 40 black and white X-ray images prepared for research purposes. See more photos from the exhibit.