Rhinoceros, also known as rhino, is a group of five extant species of odd-toed ungulates in the family Rhinocerotidae. Two of these species are native to Africa and three to southern Asia.
The rhinoceros family is characterized by its large size
(one of the largest remaining megafauna), with all of the species able
to reach one tonne or more in weight; an herbivorous diet; a thick
protective skin, 1.5–5 cm thick, formed from layers of collagen
positioned in a lattice structure; relatively small brains for mammals
this size (400–600 g); and a large horn.
They generally eat leafy material,
although their ability to ferment food in their hindgut allows them to
subsist on more fibrous plant matter, if necessary. Unlike other
perissodactyls, the African species of rhinoceros lack teeth at the
front of their mouths, relying instead on their powerful premolar and
molar teeth to grind up plant food.
Rhinoceros are killed by humans for their horns, which are bought and sold on the black market, and which are used by some cultures for ornamental or (pseudo-scientific) medicinal purposes.
The horns are made of keratin, the same type of protein that makes up
hair and fingernails. Both African species and the Sumatran Rhinoceros
have two horns, while the Indian and Javan Rhinoceros have a single
horn.
The IUCN Red List identifies three of the species as critically endangered.
The five living species of rhinoceros:
- White Rhinoceros
- Black Rhinoceros
- Indian Rhinoceros
- Javan Rhinoceros
- Sumatran Rhinoceros
- White Rhinoceros
- Black Rhinoceros
- Indian Rhinoceros
- Javan Rhinoceros
- Sumatran Rhinoceros
