Bird feet

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. Most birds have four toes, inherited together with over a hundred anatomical features from their theropod dinosaur ancestors.^[1] These four toes are arranged into four main patterns.^[2]

1. ↑ Mayr, Gerald 2016. Avian evolution. Wiley. doi:10.1002/9781119020677. ISBN 9781119020677.
2. ↑ Proctor N.S. & Lynch P.J. 1998. Manual of Ornithology: avian structure & function. Yale University Press. ISBN 0300076193