White Rhino – Ceratotherium simum
There are several theories to explain the origin of the name ‘white .from the Afrikaans ‘wyd’ or Dutch ‘wijd’ (meaning wide) not a color, as they are not white at all. There are the folds of skin near the top of the forelimbs, and in the flank where the upper part of each hindlimb joins the body. The skin color is gray but is modified by the earth color used for the sketches.
Limbs are thick-set, with three toes bearing broad, stout nails on each foot. Tail short with a sparse fringe of bristly hairs. Males have no scrotum and the muscular penis points backward when enclosed in its sheath. There are preputial glands. Apart from the genitals, there is little sexual dimorphism, except that males attain a body mass about one-third larger than females and have considerably heavier heads, chests, and necks.
Two keratinous horns devoid of a bony nucleus grow in tandem on the muzzle, the front longer than the back. The horns are made up of a mass of tubular filaments similar in substance to hair and are in fact growths of the skin not attached to the bone of the skull. The front horn has a straighter transverse edge in front when compared with that of the Black Rhino.
Male horns have a greater mean anterior basal circumference relative to female horns, while female usually bears the front horns thinner and sometimes longer than a male adult. Males’ horns are heavier than female ones. The average horn mass of adult white rhinos is 5.2 kg for the anterior horn and 1.9 kg for the posterior horn. No difference between adult sexes in intrinsic anterior horn growth (mean rate of 50 mm per year; range 25–66); intrinsic horn growth the rate is fast in young animals, about 150 mm during the first year, but the growth rate of the front horns decreases with age.
Strongly constructed zygomatic arches provide firm fixation of the masseter muscles that operate the lower jaw. Massive lower jaw, very wide condyles which fit into deep cavities. Adult dental formula is I 0 /0, C 0 /0, P 3 /3, M 3 /3 = 24. Four premolars in deciduous dentition; no incisors or canines in deciduous dentition, which are sometimes present in Black Rhinos. The upper and lower second molars are the largest of the cheek teeth.
C.s. simum: Southern White Rhinoceros; southern Africa only, though introduced to Kenya, Uganda (where the species, but not subspecies, formerly occurred) and Zambia.
C. s.cottoni: northern white rhinoceros; formerly in Central African Republic, Chad, Sudan, Uganda, and NE DR Congo; now probably extinct in the wild. Dorsal outline of the skull less concave than in the southern subspecies, a shorter toothrow length, slightly longer legs relative to body length, slightly smaller size overall, and generally higher head carriage.