How are mammals different from representatives of other classes of vertebrates?

Mammals have the following distinguishing features from other classes of chordates:

Have lactic (mammary) glands;
The skin has a hairline – wool;
The presence of the auricle. Although its form is different for representatives of different orders, and even genera;
A large muscle – the diaphragm that separates the chest cavity from the abdominal cavity;
The presence of sweat glands in the skin;
Differentiation of teeth into incisors, canines, small and large molars;
Good development of the salivary glands;
In the reproductive system, most representatives have an organ – the uterus.