The hairy frog is also notable in possessing retractable “claws” (though unlike true , they are made of bone, not ), which it may project through the skin, apparently by intentionally breaking the bones of the toe. In addition, the researchers found a small bony nodule nestled in the tissue just beyond the frog’s fingertip. When sheathed, each claw is anchored to the nodule with tough strands of collagen, but, as  discovered firsthand, when the frog is grabbed or attacked, the frog breaks the nodule connection and forces its sharpened bones through the skin.