1. Their skin is covered with hair.
2. The outer ear is attached to the pinna. The middle ear consists of malleus, incus and stapes. Cochlea exists in the inner ear. Dr. Siddiq Publications
3. Mature females have active mammary glands. Cubs drink mother’s milk.
4. Between the thorax and abdomen is a membrane called the diaphragm.
5. The crown of the head is connected to the spinal cord by two occipital condyles.
6. They have sweat glands and scent glands.
7. They are endothermic or warm-blooded animals. That is, their body temperature does not change with the rise and fall of the environment temperature.
8. Their red blood cells are without nucleus (exception – camel).
9. Their brains are developed and they have all the tantras.
10. They have 12 pairs or 24 cranial nerves.
11. They have teeth in both jaws.
12. The heart has four chambers. Two atria and two ventricles.
13. The circulatory system is advanced. Bi-cycle or double circulation. Systemic and pulmonary cycles are seen.
14. They have vocal cords in their larynxes. The glottis has a covering called the epiglottis.
15. Their poison is internal. They bear the uterus and give birth to babies.
[key words to remember features: hair, pinna, cochlea, cochlea, mammary gland, diaphragm, sweat gland, olfactory gland, endothermic, red blood cell, cranial nerve, tooth, heart, circulatory system, vocal card, uterus] Dr. Siddiq Publications