Class Mammalia: All the animals relating to class Mammalia are termed as mammals. In the animal kingdom, one of the most developed species are mammals that are categorized under Vertebrata. Around 6,000 species of living mammals are present on the planet. They are well adapted to their surroundings such as from deserts, oceans, and polar regions to rivers and rainforests, etc because of their distribution all over the world They are depicted by the presence of mammary glands which helps them to feed their offsprings.

Main Characteristics of Class Mammalia

Below is the list of characteristics of class Mammalia:

• Sweat glands and oil glands are found on the skin.
• Presence of mammary glands, which aid in the production of milk to feed their young.
• All these animals are warm-blooded.
• Their hearts are divided into four chambers.
• The tooth comes twice in these animals (Diphyodont).
• No nucleus is found in its red blood cells (except in camels and llama). 
• The skin of mammals has hair.
• External ear (pinna) is present in mammals.

• They are of different types – heterodont and thecodont. 

• The skull’s form is dicondylic.

• A four-chambered heart is found in mammals. Both the renal portal and sinus venous systems are absent.
• They possess muscular diaphragms.
• They respire through lungs.

Classification Of Class Mammalia

Mammalia has the largest class in the animal kingdom. Based on their reproduction, they are classified into three subclasses:

• Eutheria

• Metatheria

• Prototheria

Eutheria

Mammals under this subclass give birth to young ones. The young ones are developed inside the mother and derive nutrition through the placenta from the mother. Furthermore, it consists of 19 orders, few of which are:

Metatheria

Mammals belonging to this sub-class give birth to immature young ones, hence they stay in their mother’s pouch until they mature. For eg., Marsupials and Kangaroos. They are divided into seven different orders:

Prototheria

Also known as Monotremes, the sub-class Prototheria consists of egg-laying mammals. It has one order having 6 species

Order: Monotremata

Example: Duckbilled platypus, Echidna

General Classification of Class Mammalia

The scientists have also classified the mammals on a general basis which makes it easy to learn about the mammals and their distinguishing characteristics.

JOIN OUR TELEGRAM CHANNELS
Biology Quiz & Notes	Physics Quiz & Notes	Chemistry Quiz & Notes

---

Follow on Facebook

By Team Learning Mantras