The New Encyclopaedia Britannica in 30 Volumes - Macropaedia 15 [antikvár]

Proboscidea The order Proboscidea comprises three suborders and about 300 species of terrestrial mammals. All but two species, the Asiatic, or Asian, elephant (Elephas maximus) and the African elephant (Loxodonta africana), are extinct. The elephants are the largest surviving land animals and, among the mammals, are exceeded only , by the whales in size. The Proboscidea are characterized by columnar limbs, bulky bodies, and elongated snouts. In recent forms, testes are internal. The snout is a long boneless proboscis, or trunk; it is a combination of the upper lips, palate, and nostrils. Some of the incisor teeth develop into tusks. One extinct suborder (Deinotherioidea) lost the upper tusks; certain others have lost the lower ones and evolved upper tusks of dentine from which the enamel has partially or completely disappeared. The canine teeth were generally Palaeomastodon Drawing by Christian D. Olsen Mammut Asiatic elephant Elephas maximus African elephant Loxodonta africana Figure 1: Representative fossil and living proboscideans. repressed in all groups, and the cheek teeth developed rows of blunt cones or ridges. In later forms, the temporary teeth were replaced by permanent ones, which are pushed by an escalator-like movement along a horizontal plane, so that the front teeth were replaced by teeth moving forward from the rear. The skull, which originally was elongated, became shorter, higher, and bulkier in later forms. The back of the eye orbit remained open instead of forming a complete bony ring, and the nasal opening in all Proboscidea is at a higher horizontal plane than the eye sockets. The neck shortened as the animals evolved larger, higher bodies and an elongated trunk that also functions as a hand. The skull has enlarged out of proportion to the brain in order to serve as an anchor for the trunk and to support the heavy dentition. This order occurs in all the continents except Australia. Fossils of proboscideans provide valuable information about early humans who were their contemporaries. general features Size range and distribution. In Europe, the landmass that broke up to form the islands of the Mediterranean Sea harboured proboscideans. Three fossil species have been found in Malta; one had had a height of 2.1 metres, or 6.9 feet (Palaeoloxodon mindriensis), another a height of 1.5 metres, or 4.9 feet (P. melitensis), and the third was less than one metre, or about three feet (P. falconeri). P. creticus of Crete was 1.5 metres, and P. cypriotis of Cyprus was 0.9 metre (three feet) in height. In North America, a Mammuthus isolated on Santa Rosa Island, off the coast of southern California, was probably derived from Mammuthus meridionalis, a species that stood 4.2 metres (13.8 feet) at the shoulders. Elephas maximus asurus lived in Iran and Syria. Early drawings of the animal and fragmentary skeletal remains indicate that it was the largest subspecies of the Asian elephant. The war elephants employed by Pyrrhus in 255 bc and engraved upon Roman seals show animals of unusual size. "Saras," which signified "the Syrian," was the outstanding animal in the elephant battle squadron of the Carthaginian general Hannibal. In 1500 bc elephants (Elephas maximus rubridens) existed in China as far north as Anyang, in northern Honan Province. Writings from the 14th century state that elephants were still to be found in Kwangsi Province. Man as well as other environmental factors exterminated the woolly mammoth (Mammuthus primigenius) and the imperial mammoth (M. imperator) about 10,000 years ago. Several races of the living species of Asian and African elephants also died out by about 1500 bc. The small North African race became extinct by the 2nd century ad, and some of the American mastodons, such as Cuvieronius postremus of South America, died out as recently as the 4th century ad. The large African bush elephants (Loxodonta africana) were exterminated from the Transvaal in South Africa early in the 20th century, but they still occur over much of the continent south of the Sahara Desert. A smaller elephant inhabits the forests of western equatorial Africa, particularly in the Congo region. It is considered by some to be a subspecies (Loxodonta africana cyclotis) of the African elephant; others believe it to be represented by several subspecies; still others consider it to be a separate species (L. cyclotis). In Asia, elephants have been exterminated from Iran, Iraq, Afghanistan, the northwestern part of India, and from much of the Malay Peninsula, Java, and the greater part of Borneo and Sri Lanka (formerly Ceylon). IsoEarly human records elephants