Just about everyone knows that birds have hollow bones. The humerus, clavicle, sternum, pelvic girdle, and lumbar and sacral vertebrae are all hollow. And we were taught in elementary school that ...

No, not all bird bones are hollow. Birds have a mix of pneumatic (air-filled, "hollow") bones and marrow-filled bones, and the exact pattern varies significantly by species and even by individual bone ...

Paleontologists in Argentina recently found the first unambiguous evidence that a group of theropod dinosaurs had hollow bones capable of holding air sacs – an ability that helps birds fly, according ...