The black rhinoceros or hook-lipped rhinoceros (Diceros bicornis) is a species of rhinoceros, native to eastern and central Africa including Kenya, Tanzania, Cameroon, South Africa, Namibia, Zimbabwe, and Angola. Although the rhinoceros is referred to as black, its colors vary from brown to gray. The other African rhinoceros is the white rhinoceros (Ceratotherium simum).
The word "white" in the name "white rhinoceros" is a misinterpretation of the Afrikaans word wyd, itself derived from the Dutch word wijd for wide, referring to its square upper lip, as opposed to the pointed or hooked lip of the black rhinoceros. These species are now sometimes referred to as the square-lipped (for white) or hook-lipped (for black) rhinoceros.
The species overall is classified as critically endangered, and one subspecies, the western black rhinoceros, was declared extinct by the IUCN in 2011. The species was first named Rhinoceros bicornis by Carolus Linnaeus in the 10th edition of his Systema naturae in 1758. The name means "double-horned rhinoceros". There is some confusion about what exactly Linnaeus conceived under this name as his species was probably based upon the skull of a single-horned Indian rhinoceros (Rhinoceros unicornis), with a second horn artificially added by the collector.
Such a skull is known to have existed and Linnaeus even mentioned India as origin of this species. However he also referred to reports of early travelers about a double-horned rhino in Africa and when it emerged that there is only one, single-horned species of rhino in India, "Rhinoceros" bicornis was used to refer to the African rhinos (the white rhino only became recognised in 1812). In 1911 this was formally fixed and the Cape of Good Hope officially declared the type locality of the species.
The adult black rhinoceros stands 132-180 cm (52-71 in) high at the shoulder and is 2.8-3.8 m (9.2-12 ft) in length, plus a tail of about 60 cm (24 in) in length. An adult typically weighs from 800 to 1,400 kg (1,800 to 3,100 lb), however unusually large male specimens have been reported at up to 2,199-2,896 kg (4,850-6,380 lb). The females are smaller than the males. Two horns on the skull are made of keratin with the larger front horn typically 50 cm (20 in) long, exceptionally up to 140 cm (55 in).