References to horned rabbits may originate in sightings of rabbits affected by the Shope papilloma virus, named for Richard E. Shope, M.D., who described it in a scientific journal in 1933. Shope initially examined wild cottontail rabbits that had been shot by hunters in Iowa and later examined wild rabbits from Kansas. They had "numerous horn-like protuberances on the skin over various parts of their bodies. The animals were referred to popularly as 'horned' or 'warty' rabbits." Legends about horned rabbits also occur in Asia and Africa as well as Europe, and researchers suspect the changes induced by the virus might underlie at least some of those tales.