Biologists at Harvard University have determined that some African frogs carry concealed weapons: When threatened, these species puncture their own skin with sharp bones in their toes, using the bones as claws capable of wounding predators.
The unusual defense mechanism is described by Harvard’s David C. Blackburn, James Hanken, and Farish A. Jenkins, Jr., in a forthcoming issue of the journal Biology Letters.
“It’s surprising enough to find a frog with claws,” says Blackburn, a doctoral student in Harvard’s Department of Organismic and Evolutionary Biology. “The fact that those claws work by cutting through the skin of the frogs’ feet is even more astonishing. These are the only vertebrate claws known to pierce their way to functionality.”
“Most vertebrates do a much better job of keeping their skeletons inside,” he adds.