Mammals are among the most adaptable animals on the planet. They are found on every continent and in every ocean, and range in size from tiny bumblebee bats to enormous blue whales. One reason for ...

Millions of years ago, ancient land-dwelling mammals returned to the sea. Their bodies became streamlined for swimming, articulated fingers turned into flippers and fins, hypnotic songs slowly ...

These uniquely American mammals are featured in National Geographic Kids' January edition. A pair of 7-week old red wolf pups explore their habitat at the Museum of Life and Science in Durham, N.C ...

Read a National Geographic magazine article about the rise of mammals, and get information, facts, and more about the evolution of mammals.

The first mammals first lived some 160 million years ago, in a world ruled by reptiles. And now scientists suggest that hiding in the dark from these terrifying beasts may have left an imprint in ...