Mammal+Fast+Facts

 ® =Fast Facts: = All mammals have four limbs. Even elephants and whales have hair.   Mammals have been alive for about 200 million years.  There are about 5,400 different species of mammals alive today. There are three different kinds of mammals, placental mammals, marsupials, and monotremes.  Out of 5,400 species of mammals, three (the monotremes) lay eggs.