Fanged FrogBoasting "crazy" evolutionary adaptations, a new group of so-called fanged frogs—cousins of this Luzon fanged frog (file picture)—has been discovered on the Indonesian island of Sulawesi, according to biologist Ben Evans.During a recent expedition, 13 new "fanged" species were seen on Sulawesi for the first time, 9 of them new to science, according to a new study led by Evans, a biologist at McMaster University in Canada.The "fangs" aren't teeth but bony jaw protrusions—some of which aren't visible past the gumline, said Evans, whose study was published in the August issue of the journal The American Naturalist.Scientists have yet to discover the fangs' purpose, but one possibility is that the frogs use the spikes to help capture food in fast-moving water. The frogs with the largest fangs seem to prey on fish or tadpoles.(See "'Vampire Flying Frog' Found; Tadpoles Have Black Fangs.")—Rachel Kaufman

Photograph courtesy Rafe M. Brown