DIVERSITY OF MAMMALS

SUMMARIZED DIVERSITY OF MAMMALS

1.   Order Edentata – Primitive, toothless, anteaters, armadillos & sloths 
2. Order Pholidota – characterized by horny scale covering their body. The horny scales are derived from fused bundles of hair. Only one genus – Manis

 3. Order Macroscelidea - commonly called elephant shrews. Entomophagous 
4.      Order Largomorpha. The rabbits & hares. They are all herbivores of wide distribution. 
5.      Order Rodentia are the gnawing mammals. [40% of all mammals, 1,591 species]. The important families including:

i.                    Family Sciuridae e.g. squirrels

ii.                  Family Muridae e.g. rats & mice

iii.                Family Castoridae e.g. beavers

iv.                Family Erethizontidae e.g. porcupines

v.                  Family Geomyidae (pocket gophers)

vi.                Family Crecetidae e.g. voles, lemmings etc.

6.      Order Insectivora: Mostly underground (e.g. Sorex Cincereus). They include shrews, hedgehogs & moles. They are believed in evolutionary term to be close to the monotremes.

7.      Order Carnivora: Thee dogs, wolves, cats, and bears as well as weasels. Carnivorous. The common families include:

8.      Order Pinnipedia: Marine mammals. Carnivores. Characteristically, their limbs are modified into flippers used for swimming. E.g the sea lions, walruses and seals.

9.      Order Scandentia: These are tree shrews. They are small mammals resembling squirrels.

10.      Order Dermoptera: Flying Lemur. Only one genus (Galeopithecus) with  just two species.

11.      Order Chiroptera: Bats. The only truly flying mammals. Fore-limbs modified into wings. There  are about 950 extant species.

12.        Order Cetacea: Fish-like mammals. Aquatic eg Whales, Dolphins and Porpoises. No posterior limbs. Fore-limbs modified into flippers. No hair covering on their body except for restricted location such as the muzzle. Except for the mammary gland, there are no glands in the skin. They also lack pinnae.

13.        Order Sirenia: Sea cows and manatees. These are also aquatic mammals. They have large head but lack hind limbs. The fore limbs are modified into flippers.

14.        Order Proboscidea:  – the elephants. They are the largest land animals. Characteristically, the upper incisors are prolonged to form tusks while the molars are well developed. Only two species of elephants exists viz:

i.                    Elephas maximus – the Indian elephant having relatively small ears.

ii.                  Loxodonta africana – the African elephant having relatively large ears.

15.        Order Hyracoidea: this is the group of the hyraxes (Coneys). They are herbivorous and widely distributed in Syria and Africa. They resemble rabbits. They live in colonies.

16.        Order Tubulidentata: this is the Aardvark order. Only one species and its found only in Africa. It is a peculiar animal in that it has body like a pig. Its teeth are hollow.

THE UNGULATES: These are animals with hooves and teeth adapted for chewing. They are into two orders namely Perrisodactyla and Artiodactyla.

17.        Order Perrisodactyla: These are the odd-toed mammals with hooves. The toes are either one or three, but each has a cornified hoof. Eg the Zebras, Asses, Tapirs and Rhinoceros.

18.        Order Artiodactyla: these are the even-toed hoofed mammals. Most have two toes e.g. the hippopotamus while others have four toes. Animals in this order are grouped into three sub-orders

19.        Order Primates: The most highly developed mammals. Include include the lemurs, monkeys, apes, humans and others. Members of this group have five digits leaving flat nail on the forelimbs and hand limbs. Except humans, they all have their body covered with hair. Their forelimbs are mainly adapted for grasping. Characteristically, members of the order lack claws, scales, horns and hoofs.