Spur (zoology)

Rooster with spurs on the lower legs.
Spur-winged lapwing in flight with wing spurs clearly visible on the leading edge of the wings.

A spur is an outgrowth of bone covered in a sheath of horn found in various anatomical locations in some animals. Unlike claws or nails, which grow from the tip of the toes, spurs form from other parts of the foot, usually in connection with joints where the toes meet the foot or the foot meets the long bones.[1] Spurs are most commonly found on the hindfeet, though some birds possess spurs at the leading edge of the wings.[2]

  1. ^ Fisher, H.I. (1940). "The occurrence of vestigial claws on the wings of birds". American Midland Naturalist. 23 (1): 234–243. doi:10.2307/2485270. JSTOR 2485270.
  2. ^ Rand, A.L. (1954). "On the Spurs on Birds' Wings" (PDF). The Wilson Bulletin. 66 (2): 127–134. Retrieved 16 November 2012.