How did horse feet change during evolution?

The evolution of the horse's foot is a well-documented transition from a padded, multi-toed structure to the specialized, single-hoofed limb of modern equines. This process reflects an evolutionary trend toward increased size, limb length, and specialization for swift running in open environments.123

• Early Ancestors: The earliest ancestral horse, Eohippus (or Hyracotherium), lived during the Eocene and possessed padded feet with four functional toes on the forefeet and three on the hind feet.23
• Reduction of Digits: Over millions of years, the number of toes decreased. By the Oligocene, the genus Mesohippus had three functional toes on all feet and still retained footpads.23
• Specialization for Speed: As horses adapted to grazing on grasslands, their limbs became more rigid and specialized for fore-and-aft movement. In forms like Merychippus, the footpad was lost, and the central toe became dominant, bearing most of the body's weight.23
• Modern Equids: In the genus Equus, the lateral toes were reduced to vestigial splint bones. Modern horses walk on the tip of a single, highly developed digit protected by a solid hoof, which provides the necessary support and spring mechanism for efficient locomotion.124