A nail is a horn-like envelope covering the dorsal aspect of the terminal phalanges of fingers and toes in humans, most non-human primates, and a few other mammals. Nails are similar to claws, which are found on numerous other animals. Fingernails and toenails are made of a tough protein called keratin, as are animals' hooves and horns. The mammalian nail, claw, and hoof are all examples of unguis (plural ungues) [Wikipedia: http://en.wikipedia.org/wiki/Nail_(anatomy)].
Hierarchy: 2
Parent: appendages
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