Land vertebrates have feet. The organization of their feet varies. Two factors come into play: weight and lifestyle.

1. Plantigrade: heavy animals usually put their heels down to support their weight.

2. Unguligrade: large animals with hooves.

3. Digitigrade is usually reserved for lighter animals. It means to walk on the toes.

Comparison of lower limb structure. From left to right: plantigrade, digitigrade and unguligrade.