Normally, the oldest name would be used, but a 1977 ruling by the International Commission on Zoological Nomenclature established the proper genus name as Dicerorhinus. In 1868, John Edward Gray proposed the name Ceratorhinus. Constantin Wilhelm Lambert Gloger proposed the name Dicerorhinus in 1841. Joshua Brookes considered the Sumatran rhinoceros with its two horns a distinct genus from the one-horned Rhinoceros, and gave it the name Didermocerus in 1828. Carl Linnaeus originally classified all rhinos in the genus, Rhinoceros therefore, the species was originally identified as Rhinoceros sumatrensis or sumatranus. The specific epithet sumatrensis signifies 'of Sumatra', the Indonesian island where the rhinos were first discovered. In 1814, the species was given a scientific name by Johann Fischer von Waldheim. Drawings of the animal, and a written description, were sent to the naturalist Joseph Banks, then president of the Royal Society of London, who published a paper on the specimen that year. The first documented Sumatran rhinoceros was shot 16 km (9.9 mi) outside Fort Marlborough, near the west coast of Sumatra, in 1793. Taxonomy and naming First drawing of the first specimen known to Western science, by William Bell, 1793 There are fewer than 80 left in existence.

The species is now considered to be locally extinct in that country, and only survives in Indonesia. Malaysia's last known bull and cow Sumatran rhinos died in May and November 2019, respectively. The Indonesian ministry of Environment, began an official counting of the Sumatran rhino in February 2019, planned to be completed in three years. In March 2016, a Sumatran rhinoceros (of the Bornean rhinoceros subspecies) was spotted in Indonesian Borneo. Though a number of rhinos died once at the various destinations and no offspring were produced for nearly 20 years, the rhinos were all doomed in their soon-to-be-logged forest. There was little or no information about procedures that would assist in ex situ breeding. The species is much better studied than the similarly reclusive Javan rhinoceros, in part because of a program that brought 40 Sumatran rhinos into captivity with the goal of preserving the species. It is the most vocal rhino species and also communicates through marking soil with its feet, twisting saplings into patterns, and leaving excrement. The Sumatran rhino is a mostly solitary animal except for courtship and offspring-rearing. A tiny population was discovered in East Kalimantan in early 2016. In 2015, researchers announced that the Bornean rhinoceros had become extinct in the northern part of Borneo in Sabah, Malaysia. The species was extirpated in Malaysia in 2019, and one of the Sumatran populations may already be extinct. It is now critically endangered, with only five substantial populations in the wild: four in Sumatra and one in Borneo, with an estimated total population of fewer than 80 mature individuals. The Sumatran rhinoceros once inhabited rainforests, swamps and cloud forests in India, Bhutan, Bangladesh, Myanmar, Laos, Thailand, Malaysia, Indonesia and southwestern China, particularly in Sichuan. A coat of reddish-brown hair covers most of the Sumatran rhino's body. Like both African species, it has two horns the larger is the nasal horn, typically 15–25 cm (5.9–9.8 in), while the other horn is typically a stub.

It is the smallest rhinoceros, although it is still a large mammal it stands 112–145 cm (44–57 in) high at the shoulder, with a head-and-body length of 2.36–3.18 m (7 ft 9 in – 10 ft 5 in) and a tail of 35–70 cm (14–28 in). The Sumatran rhinoceros ( Dicerorhinus sumatrensis), also known as the Sumatran rhino, hairy rhinoceros or Asian two-horned rhinoceros, is a rare member of the family Rhinocerotidae and one of five extant species of rhinoceros it is the only extant species of the genus Dicerorhinus.

Sumatran rhinoceros drawing