Misleading is the apparent mismatch: a house cat claw rests sheathed against the toe, while a lion carries the same folded blade beneath a paw built for bringing down large prey. The hardware is ancient. In both animals, an elastic ligament helps hold the keratin claw clear of the ground until contraction of the flexor digitorum profundus rotates the distal phalanx and exposes it. This is a claw r...More