Gorillas, and sometimes chimpanzees, use a style of locomotion called knuckle-walking, where they walk on all fours with the fingers of their forelimbs.rolled into the hand, putting pressure on their knuckles. Gorillas can move at great speeds using this method.

Giant anteaters and platypus are also knuckle-walkers. Giant pangolins also sometime walk on their knuckles. The chalicotheres were large prehistoric knuckle-walkers that looked something like at cross between a rhino and a gorilla.

Knuckle-walking tends to evolve when the fingers of the forelimb are specialised for tasks other than locomotion on the ground. In the gorilla the fingers are used for the manipulation of food, and in chimpanzees for the manipulation of food and for climbing. In anteaters and pangolins the fingers have large claws for opening the mounds of social insects. Platypus fingers are extensively webbed for swimming.

primatology | Locomotion