rhinoceros

Large grazing mammal with one or more horns on its snout. Rhinoceroses have thick, loose skin with little hair, stumpy, powerful legs with three toes on each foot. The largest species (the one-horned Indian rhinoceros) can grow up to 2 m/6 ft high at the shoulder and weigh 2,300–4,000 kg/5,060–8,800 lb. Rhinoceroses eat grass, leafy twigs, and shrubs, and are solitary. They have poor eyesight but excellent hearing and smell. Although they look clumsy, rhinos can reach speeds of 56 kph/35 mph. In the wild they are thought to live for about 25 years, and up to 47 in captivity. There are five species: three Asian and two African, all in danger of extinction.

Species
The largest rhinoceros is the one-horned Indian rhinoceros Rhinoceros unicornis, which has a rough skin, folded into shieldlike pieces; the African rhinoceroses are smooth-skinned and two-horned. The African black rhinoceros Diceros bicornis is 1.5 m/5 ft high, with a prehensile (grasping) upper lip for feeding on shrubs, and sometimes a smaller third horn. The broad-lipped (‘white’) rhinoceros Ceratotherium simum is actually slaty-grey, with a squarish mouth for browsing grass. The Javan rhinoceros R. sondaicus is near extinction, as is the two-horned Sumatran rhinoceros Dicerorhinus sumatrensis.

In danger
The Javan rhino is now one of the world's rarest mammals, and is included on the CITES list of endangered species. In 1998 there were 50–60 Javan rhino Rhinoceros sondaicus sondaicus in Ujing Kulon National Park, Java, and an estimated five of the subspecies R. s. annamiticus in Vietnam. The total population of Indian rhinoceroses (1995) consists of about 2,000 animals.

Huge ancestor
An extinct hornless species, the baluchithere (genus Baluchitherium), reached 4.5 m/15 ft high.

Classification
Rhinoceroses belong to the phylum Chordata, subphylum Vertebrata, class Mammalia (mammal), order Perissodactyla (odd-toed ungulates), suborder Ceratomorpha, family Rhinocerotidae. Today there are four genera with five remaining species: the great Indian rhinoceros (Rhinoceros unicornis), the Javan or lesser one-horned rhinoceros (R. sondaicus), the Sumatran or Asiatic two-horned or hairy rhinoceros (Dicerorhinus sumatrensis), the African black rhinoceros (Diceros bicornis) and the African white rhinoceros (Ceratotherium simum).