The team measured the wing and leg bones of 111 bat species and 149 bird species from around the world. Their dataset included X-rays of museum specimens and about a third of the new X-rays of bat ...

squirrels and "flying" lemurs actually glide or parachute by means of a furred membrane, but only bats have the structural adaptations that allow for full powered flight. The structure of the wing ...

bat wings have very little stiffness. They consist of a very flexible membrane of skin stretched across jointed bones which have a low mineral content and therefore high flexibility too.

When vertebrates moved onto land, long ago, some of them eventually became airborne, way after the insects did. There are ...