... of ribs attached to that very flexible backbone Ball-and-socket joints attach the sections of the backbone to one another, and each rib to a section of the backbone So great freedom of movement ... earth for more < /b> Ihan 100,000,000 years Some of the reptiles developed feathers on their bodies, and their forelimbs became wings In time they learned to fly, and birds came into being Birds' feathers ... time to avoid hitting the obstacle! Most people think all bats behave more < /b> or less the same way, but since there are more < /b> than 2,000 kinds of bats, you can see why < /b> this is not so There are bats...