Types of bird feet

Bird left leg and pelvic girdle skeleton

Bird feet are adapted to the life they lead, and the patterns are often use in avian classification. They are derived from the basic limb of ancestral tetrapods, the pentadactyl limb. Humans (and other primates) have the original five fingers and five toes. Birds have no more than four toes, inherited together with over a hundred anatomical features from theropod dinosaurs. These four toes are arranged into four main patterns.