Chordate Zoology - Textbook - Y. V. Tsaryk - 2013

Chapter 5. SUPERCLASS TETRAPODS (LAND VERTEBRATES) TETRAPODA, seu QUADRIPEDA.

ANAMNIOTES (ANAMNIA) AND AMNIOTES (AMNIOTA)

5.4. CLASS MAMMALS, OR BEASTS, MAMMALIA, seu THERIA

5.4.4. Systematics and Characteristics of Representatives of the Main Orders of the Class Mammalia

5.4.4.2. Subclass Theria

5.4.4.2.11. Order Proboscidea (Elephant-like Elephantiformes)

These are the largest terrestrial animals, reaching a height of 3-4 m and a mass of 4-5 t; they were numerous and widespread during the Tertiary period. The trunk is a highly elongated muscular Nose that has fused with the upper lip and is supported at its base by Cartilage; it is used as a prehensile organ that simultaneously Functions for Touch and smell. The limbs are five-toed, with small hooves and a flat sole; beneath the Skin of the sole lies a gelatinous, elastic pad that ensures silent movement over the ground.

The skin is thick and, in modern species, hairless. The tusks are paired upper incisors that grow continuously and protrude far from the Oral Cavity; they grow throughout life. On each side of the jaw, there is only one functional molar at a time; when it wears down, it is replaced by the next one, which has developed by then. They reach sexual maturity at 10-16 years of age and live up to 50-80 years. After a gestation period of 18-22 months, the female gives birth to a single calf weighing about 100 kg. In the Asian elephant Elephas maximus, only males have tusks; they are easily domesticated but usually do not breed in captivity. The African elephant Loxodonta africana (Fig. 5.74, 22) is larger; females also possess tusks; they are difficult to domesticate. In recent years, the existence of two distinct elephant species in Africa has been proven: the African forest elephant Loxodonta cyclotis and the African savanna elephant Loxodonta africana.

During the Quaternary period, vast territories from the tundra to the steppes were inhabited by the woolly mammoth Mammuthus primigenius, which had long reddish-brown fur and large, curved tusks. They were also abundant in Ukraine, particularly in the Dnipro basin, as evidenced by the fossil remains of these animals. Well-preserved mammoth remains are found in the permafrost of Siberia. The most valuable of such fossil discoveries worldwide is the famous "Berezovka mammoth," whose taxidermy mount is exhibited in the Zoological Museum in St. Petersburg.