Features of Mammals Makes Them Unique
Mammals are animals that give birth to live ones and feed them with milk. It is the unique features of mammals that make them stand apart from other animal species. Mammals are class of animals that has vertebrates. The backbone of all the mammals is made up of individual vertebras. They are warm-blooded animals. The body temperatures of mammals are comparatively very high because of the high metabolism rate. Mammals are Tetrapods, which means that they have four limbs. Some use four limbs to walk while other requires only two. Some can walk on two limbs as well as four limbs.
In mammal species all of them grow hair or fur on them. Hair grows from follicles in the skin. Fur allows them to maintain body temperature. Fur protects some mammals from extreme cold conditions. In some mammals fur acts as an indicator. The other features of mammals are its reproduction and respiratory system. The respiratory system of mammals contains a pair of lungs. Mammals breathing rate varies. Blue whale breathes once in every two hours while rodents have a breathing rate of 150 in a minute. Most of the mammals give birth to live ones but a group of mammals named monotremes lays eggs.
Mammals first appeared on earth 200 million years ago. Mammals have teeth that differ in size for different mammals. The most important feature of mammals is the presence of mammary glands. Both males and females possess mammary glands, but the mammary gland reaches full growth only in females. Mammal’s heart is four chambered and helps them to maintain constant temperature in the body. The inner ear of a mammal include three bones namely maleus, incus and stapes. Mammals grow rapidly after birth and the rate decreases during adult stage. To maintain the body temperature mammals must eat ten times greater than ectothermic organisms. At present, mammals are facing the threat of extinction and must be protected at any cost.

