About mammal
Mammals are a group of vertebrate animals constituting the class Mammalia, characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex, fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla. The next three are the Primates, the Artiodactyla, and the Carnivora.

Mammal

gray rhinoceros on grasses
gray rhinoceros on grasses
close-up photography of black and white Siberian husky
close-up photography of black and white Siberian husky
tuxedo cat on green plant
tuxedo cat on green plant
adult white tiger
adult white tiger
grayscale photo of lion face
grayscale photo of lion face
white sheep on brown field during daytime
white sheep on brown field during daytime
brown lion on water during daytime
brown lion on water during daytime
bird on buffalo at daytime
bird on buffalo at daytime
brown lion on green grass field
brown lion on green grass field
dolphin swimming in body of water
dolphin swimming in body of water
red fox on concrete road
red fox on concrete road
brown fox on snow field
brown fox on snow field
two kangaroos
two kangaroos
orange leopard
orange leopard
brown and black tiger lying on gray rock
brown and black tiger lying on gray rock
white animal on desert during daytime
white animal on desert during daytime