Black Rhinoceros

Verified Timeline

Lore & Background

The origin of the name 'white rhinoceros' is unknown, but one popular, though discredited, theory for the origin of the name is a mistranslation of the Dutch word 'wijd' (meaning 'wide' in English) into English. The term 'wide' would have referred to the rhinoceros's broad, square mouth, distinguishing it from the narrow-lipped black rhinoceros. According to this theory, early English-speaking settlers in South Africa misinterpreted 'wijd' as 'white'. Ironically, Dutch and Afrikaans later adopted 'white rhino' (as witrenoster in Afrikaans) as a calque from English, a development suggesting the English term was established before any potential codification of 'wijd' by Dutch writers for this species. Indeed, a review of Dutch and Afrikaans literature by Rookmaaker (2003) found no written evidence of 'wijd' ever being used to describe the rhinoceros, indicating its use, if any, was likely confined to oral language. An alternative, more descriptive name for the white rhinoceros is the square-lipped rhinoceros, though it is less commonly used. The generic name, Ceratotherium, was given by zoologist John Edward Gray in 1868. It derives from the Greek kéras (κέρας), meaning 'horn', and thēríon (θηρίον), meaning 'beast'. The specific epithet, simum, comes from the Greek simos (σιμός), meaning 'flat-nosed', referring to the animal's broad, flat snout.

In Their Own Story

The modern white rhinoceros was initially thought to be descended from Ceratotherium praecox, a species from approximately seven million years ago with remains found at Langebaanweg near Cape Town. However, a 2005 review of African fossil rhinos by Denis Geraads proposed that while the Langebaanweg species belongs to the genus Ceratotherium, it is not C. praecox. Geraads argued that the type specimen of C. praecox exhibits closer affinities with the black rhinoceros (Diceros bicornis) and should therefore be classified as Diceros praecox. It had been suggested by Turner (2004) that the modern white rhino's elongated skull—compared to that attributed to C. praecox—evolved to facilitate grazing on shorter grasses as Africa experienced long-term drying conditions. If C. praecox is indeed Diceros praecox, its shorter skull could instead indicate a browse diet. Further complicating this interpretation, carbon isotope analysis of teeth from fossils assigned to Ceratotherium at Makapansgat, South Africa, indicated that these animals incorporated over 30% browse into their diet, unlike the exclusively grass-eating modern Ceratotherium simum. Based on these considerations, Geraads (2005) proposed an alternative lineage for the white rhino: Ceratotherium neumayri → Ceratotherium mauritanicum → C. simum, with the Langebaanweg rhinos considered an as-yet-unnamed Ceratotherium species, and black rhinos descending from C. neumayri via Diceros praecox. An alternative evolutionary scenario was proposed by Hernesniemi et al. (2011). This model posits Ceratotherium efficax (now considered synonymous with C. mauritanicum) from the Late Pliocene of Ethiopia and Early Pleistocene of Tanzania as the earliest African Ceratotherium. This species is then proposed to have diversified into C. mauritanicum in northern Africa, C. germanoafricanum in East Africa (both now extinct), and the extant C. simum. C. germanoafricanum is noted as being very similar to C. simum and has often been regarded as a fossil and ancestral subspecies of the latter. The 2011 study also casts doubt on the Miocene species Ceratotherium neumayri from southern Europe being ancestral to African species. It is likely that the common ancestor of both black and white rhinos was a mixed feeder, with the two lineages subsequently specializing in browsing and grazing, respectively. The oldest definitive fossil record of Ceratotherium simum dates to the mid-Early Pleistocene, around 1.8 million years ago, at Olduvai Gorge in Tanzania.

Reader's Guide

The white rhinoceros is the largest of the five living rhinoceros species and one of the largest megafauna in existence. Judged by mean body mass, only the three extant species of elephant surpass it. Though the body mass of individual rhinoceros often overlap with that of individual hippopotamuses, with whom it shares a habitat, the white rhinoceros weighs more on average. The white rhino's mass is evident in its large, barrel-shaped body and its immense head, which are connected by a short, powerful neck. Males (bulls) typically have a head-and-body length of 3.7–4 m (12.1–13.1 ft) and a shoulder height of 170–186 cm (5.58–6.10 ft), while females (cows) measure 3.35–3.65 m (11.0–12.0 ft) in head-and-body length and 160–177 cm (5.25–5.81 ft) at the shoulder. The tail adds approximately 70 cm (28 in) to the total length. Bulls are heavier, averaging 2,000–2,300 kg (4,410–5,070 lb), compared to cows, which average about 1,600–1,700 kg (3,530–3,750 lb). While specimens up to 3,600 kg (7,940 lb) are considered reliably recorded, claims of individuals reaching up to 4,500 kg (9,920 lb) remain unverified, making the species' maximum attainable size not definitively known. The white rhinoceros's most noticeable features are perhaps the two formidable, horn-like structures on its snout, one behind the other. These are not true horns in the bovid sense (which encase a bony core), nor are they antlers of bone like those of deer. Instead, they are solid masses of densely compacted keratin fibers, the same protein that forms human hair and fingernails. The anterior (front) horn is typically the larger and more prominent, averaging 60 cm (24 in) in length, though in some individuals, particularly cows, it can attain lengths of up to 166 cm (65 in). A single horn can weigh around 4.0 kg (8.8 lb). A prominent muscular hump is situated on the back of its neck, crucial for supporting the weight of its massive head during long periods of grazing. Due to its habit of wallowing in mud, the rhino's thick, armor-like skin, typically grey, often takes on the color of the local soil—from yellow to reddish. White rhinoceros can run up to 40 mph (64 km/h) for very short bursts. They can maintain speeds of around 30–31 mph (48–50 km/h) for a good amount of time, and they have good stamina.

Did You Know?

• The white rhinoceros is the largest extant species of rhinoceros and the most social of all rhino species.
• The northern white rhinoceros is critically endangered and on the brink of extinction; its last known male, Sudan, died in March 2018, leaving behind only two females.
• White rhinoceros can run up to 40 mph (64 km/h) for very short bursts and can maintain speeds of around 30–31 mph (48–50 km/h) for a good amount of time.
• The generic name Ceratotherium derives from the Greek kéras (κέρας), meaning 'horn', and thēríon (θηρίον), meaning 'beast'.
• The oldest definitive fossil record of Ceratotherium simum dates to the mid-Early Pleistocene, around 1.8 million years ago, at Olduvai Gorge in Tanzania.