タイトルまたは説明

Horns usually have a curved or spiral shape, often with ridges or fluting. In many species, only males have horns. Horns start to grow soon after birth and continue to grow throughout the life of the animal (except in pronghorns, which shed the outer layer annually, but retain the bony core).

Partial or deformed horns in livestock are called scurs. Similar growths on other parts of the body are not usually called horns, but spurs, claws or hoofs - depending on the part of the body on which they occur.
A horn - a permanent pointed projection on the head of various animals - consists of a covering of keratin and other proteins surrounding a core of live bone. Horns are distinct from antlers, which are not permanent.