The African Elephant
African elephants are elephants of the genus Loxodonta. The genus consists of two extant species: the African bush elephant, L. africana, and the smaller African forest elephant, L. cyclotis. Loxodonta (from Greek λοξός, loxós: 'slanting, crosswise, oblique sided' + ὀδούς, odoús: stem odónt-, 'tooth') is one of two existing genera of the family Elephantidae. Fossil remains of Loxodonta have been found only in Africa, in strata as old as the middle Pliocene. However, sequence analysis of DNA extracted from fossils of an extinct elephant species undermines the validity of the genus.
Description
One species of African elephant, the bush elephant, is the largest living terrestrial animal, while the forest elephant is the third-largest. Their thickset bodies rest on stocky legs, and they have concave backs. Their large ears enable heat loss. The upper lip and nose form a trunk. The trunk acts as a fifth limb, a sound amplifier, and an important method of touch. African elephants' trunks end in two opposing lips, whereas the Asian elephant trunk ends in a single lip. In L. africana, males stand 3.2–4.0 m (10.5–13.1 ft) tall at the shoulder and weigh 4,700–6,048 kg (10,362–13,334 lb), while females stand 2.2–2.6 m (7.2–8.5 ft) tall and weigh 2,160–3,232 kg (4,762–7,125 lb); L. cyclotisis smaller with male shoulder heights of up to 2.5 m (8.2 ft). The largest recorded individual stood 3.96 m (13.0 ft) at the shoulder and weighed 10.4 tonnes (10.2 long tons; 11.5 short tons). The tallest recorded individual stood 4.21 m (13.8 ft) at the shoulder and weighed 8 tonnes (7.9 long tons; 8.8 short tons).
Teeth
Elephants have four molars; each weighs about 5 kg (11 lb) and measures about 30 cm (12 in) long. As the front pair wears down and drops out in pieces, the back pair moves forward, and two new molars emerge in the back of the mouth. Elephants replace their teeth four to six times in their lifetimes. Around 40 to 60 years of age, the elephant loses the last of its molars and will likely die of starvation, a common cause of death. African elephants have 24 teeth in total, six on each quadrant of the jaw. The enamel plates of the molars are fewer in number than in Asian elephants.
The elephants' tusks are firm teeth; the second set of incisors become the tusks. They are used for digging for roots and stripping the bark from trees for food, for fighting each other during mating season, and for defending themselves against predators. The tusks weigh from 23–45 kg (51–99 lb) and can be from 1.5–2.4 m (5–8 ft) long. Unlike Asian elephants, both male and female African elephants have tusks. They are curved forward and continue to grow throughout the elephant's lifetime.
Credits: Wikipedia
Written By David Davidson
No comments:
Post a Comment