Characteristics of mammals:

(i) Their body is divisible into head, trunk, neck and tail. Cutaneous glands such as sweat glands, scent glands and sebaceous glands are present.

(ii) Females have mammary glands which secrete milk for the nourishment of the young.

(iii) A muscular diaphragm separates thoracic and abdominal cavities and respiration takes place through lungs only.

(iv) Two pairs of pentadactyl limbs are present. Teeth are thecodont and heterodont.

Example: Macropus and Rattus, Macaca.