The most distal of the phalanges, located within the hoof capsule (hence the name 'coffin' bone). As it is in the horse's foot, the term pedal bone is also used interchangeably. A further term for the same bone is 'P3', relating to its position as the third phalanx.

The bone is irregularly shaped with a convex dorsal (parietal) surface, a concave solar surface and an articular surface where it forms a joint with the middle phalanx (short pastern bone).