A "horn" is a pointed projection on the head of various animals consisting of a covering of keratin and other proteins surrounding a core of live bone. In mammals, true horns are found mainly among the ruminant artiodactyls, in the families Antilocapridae and Bovidae . One pair of horns is usual; however, two or more pairs occur in a few wild species and domesticated breeds of sheep. Polycerate sheep breeds include the Hebridean, Icelandic, Jacob, Manx Loaghtan, and the Navajo-Churro. 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 . 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. The term "horn" is also popularly applied to other hard and pointed features attached to the head of animals in various other families: Many mammal species in various families have tusks, which often serve the same functions as horns, but are in fact oversize teeth. These include the Moschidae , Suidae , Proboscidea , Monodontidae and Odobenidae . Polled animals or "pollards" are those of normally-horned species whose horns have been removed, or which have not grown. In some cases such animals have small horny growths in the skin where their horns would be – these are known as "scurs". Wiz Science™ is "the" learning channel for children and all ages. SUBSCRIBE TODAY Disclaimer: This video is for your information only. The author or publisher does not guarantee the accuracy of the content presented in this video. USE AT YOUR OWN RISK. Background Music: "The Place Inside" by Silent Partner (royalty-free) from YouTube Audio Library. This video uses material/images from https://en.wikipedia.org/wiki/Horn+(anatomy), which is released under Creative Commons Attribution-Share-Alike License 3.0 http://creativecommons.org/licenses/by-sa/3.0/ . This video is licensed under Creative Commons Attribution-Share-Alike License 3.0 http://creativecommons.org/licenses/by-sa/3.0/ . To reuse/adapt the content in your own work, you must comply with the license terms.

• published: 05 Aug 2015
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