Horn (anatomy)

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A ram with three horns

For other uses, see Horn.

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A horn is a pointed projection of the skin of various mammals, consisting of a covering of horn (keratin and other proteins) surrounding a core of living bone. True horns are found only among the ruminant artiodactyls,^{[citation needed]} in the families Antilocapridae (pronghorn) and Bovidae (cows, buffalo, yaks, goats, antelope etc.). These animals have one or occasionally two pairs of horns, which usually have a curved or spiral shape, often with ridges or fluting. In many species only the males have horns. Horns start to grow soon after birth, and continue to grow throughout the life of the animal.

The term "horn" is also popularly applied to other hard and pointed features attached to the head of animals in various other families:

Giraffidae: Giraffes have bony bumps covered with furred skin which look as if they ought to have horns on them, but do not.
Cervidae: Most deer have antlers, which are not true horns. When fully grown they are dead bone without a horn or skin covering; they are borne only by adults and are shed and regrown each year.
Rhinocerotidae: The "horns" of the Rhinoceros are made of keratin, but do not have a bone core.
Ceratopsidae: The "horns" of the Triceratops were extensions of its skull bones although debate exists over whether they had a keratin covering.
Monodontidae: Male narwhals have a single long tusk, a modified tooth, which looks like a horn, and is twisted like that of the fictional unicorn.

Many mammal species in various families have tusks, which often serve the same functions as true horns, but are in fact oversize teeth. These include the Moschidae (Musk deer, which are ruminants), Suidae (Wild Boars), Proboscidea (Elephants), Monodontidae (Narwhals) and Odobenidae (Walruses).

polled animals are those of normally-horned (mainly domesticated) species whose horns have been removed, or which have not grown. In some cases such pollards have small horny growths in the skin where their horns would be; these are known as scurs.

1 Animal uses of horns
2 Human uses of horns
3 See also
4 External links

[edit] Animal uses of horns

A goat with spiral horns

Wildlife have a variety of uses for horns and antlers, including fighting attacking predators and fighting members of their own species for territory, dominance and mating priority. In addition, horns may be used to root in the soil or strip bark from trees. In animal courtship there are specific species that use horns in displays of attraction. For example, the male Blue Wildebeest reams the bark and branches of trees to impress the female and lure her into his territory. Horns are also used by some animals with true horns to provide cooling. Since horns are an extension of the skin, they have blood vessels in them, allowing the horns to function as a radiator to cool the blood.

[edit] Human uses of horns

Use of animal horns is controversial, especially if the animal was specifically hunted for the horn as a hunting trophy or object of decoration or utility. Some animals are threatened or endangered to reduced populations partially from pressures of such hunting.

Some peoples use bovid horns as musical instruments, for example the shofar. These have evolved into brass instruments in which, unlike the trumpet, the bore gradually increases in width through most of its length — that is to say, it is conical rather than cylindrical. These are called horns, though made of metal.

Drinking horns' are bovid horns removed from the bone core, cleaned and polished and used as drinking vessels. (See also the legend of the Horn of plenty, or Cornucopia).

Powder horns were originally bovid horns fitted with lids and carrying straps, used to carry gunpowder. Powder flasks of any material may be referred to as powder horns.

Horn bows Horn bows are bows made from combination horn, sinew and usually wood. These material allow more energy to be stored in a short bow than wood.

Antelope horns are used in traditional Chinese medicine.

Horn can also refer to keratin, the material of which a horn is made. This is most common when a horn is used as a material in tools, furniture, decoration, and other uses. In these applications, horn is valued for its hardness, and has given rise to the expression hard as horn. Horn is somewhat thermoplastic and (like tortoiseshell) was formerly used for many purposes where plastic would now be used. Horn may be used to make glue.

Ivory comes from the teeth of animals, not horns.

"Horn" buttons are usually made from deer antlers, not true horn.