(iv) Class - Mammalia

  • Class Mammalia represents a diverse group of warm-blooded vertebrates that includes mammals.
  • Mammals are characterised by the presence of mammary glands, hair or fur on their bodies, and the ability to nurse their young with milk.


General Characteristics:

  • Mammals have a body covered in hair or fur, which provides insulation and protection.
  • They possess mammary glands that produce milk to nourish their offspring.
  • Mammals have a differentiated dentition, including various types of teeth such as incisors, canines, premolars, and molars.
  • They exhibit a wide range of sizes, from tiny bats to enormous whales.



  • Mammals respire through lungs.
  • They have a diaphragm, a muscular structure that aids in breathing by expanding and contracting the chest cavity.


Feeding Habits:

  • Mammals exhibit diverse feeding habits, including herbivory, carnivory, omnivory, and insectivory.
  • Teeth are adapted to the specific diet of each species, such as sharp incisors and canines for tearing meat or flat molars for grinding plant matter.


Circulatory System:

  • Mammals have a four-chambered heart, which ensures efficient oxygenation of blood.
  • The circulatory system supplies oxygen and nutrients to the body and removes waste products.



  • Mammals excrete nitrogenous wastes primarily in the form of urea.
  • They possess well-developed kidneys that regulate water and ion balance.



  • Mammals exhibit internal fertilisation and give birth to live young.
  • Most mammals have separate sexes and show a wide range of reproductive strategies.
  • Some species lay eggs (monotremes), while others give birth to live young (marsupials and eutherians).


Economic Importance:

  • Mammals have immense ecological importance as pollinators, seed dispersers, and regulators of prey populations.
  • Many mammals are economically important for human use, including livestock species like cows, pigs, and sheep.
  • Some mammals, such as dogs and cats, are kept as pets, while others, like horses and camels, are used for transportation and work purposes.



  • Oviparous-Ornithorhynchus (Platypus)
  • Viviparous - Macropus (Kangaroo), Pteropus (Flying fox), Camelus (Camel), Macaca (Monkey), Rattus (Rat), Canis (Dog), Felis (Cat), Elephas (Elephant), Equus (Horse), Delphinus (Common dolphin), Balaenoptera (Blue whale), Panthera tigris (Tiger), Panthera leo (Lion),Human (Homo sapiens), Bat (multiple species, e.g., Indian Flying Fox), Squirrel (multiple species, e.g., Indian Palm Squirrel).