Add Yahoo as a preferred source to see more of our stories on Google. It's difficult to consider birds similar enough to humans or dogs to think of them as mammals, though. So, are birds mammals? If ...

A REMARK made by Prof. Allen Thomson on this subject in a late number of NATURE induces me again to draw attention to some objections I offered to the placental classification in a review of Prof.

Marine mammals are mammals that rely on the ocean to survive. They include whales, dolphins, porpoises, seals, sea lions, walruses, polar bears, sea otters, manatees, and dugongs. Some are fully ...

Part 1. The historical perspective -- 1. Introduction -- 2. The history of mammals [animals] -- 3. The early radiations -- 4. The Edentata -- 5. The Pholidota -- 6. Conclusions concerning the early ...