Evidence of avian beginnings has been elusive in the fossil record because birds' light, hollow bones rapidly decompose. So far, the oldest-known bird fossil is the famous Archaeopteryx ...

Airplane wings are modeled after bird wings. The bones and muscles of the wing are also highly specialized. The main bone, the humerus, which is similar to the upper arm of a mammal, is hollow ...

Theropod dinosaurs, which also include smaller dinosaurs like Velociraptor, exhibit features strikingly similar to modern birds. Their hollow bones are a hallmark of avian physiology and are ...

Like birds, Velociraptor had hollow bones, tended nests of eggs, and probably behaved in similar ways. Despite their birdlike plumage these dinosaurs were not fliers. Their short forelimbs made ...

This was a surprise, as pterosaurs' hollow and fragile bones tend ... had internal ridges that spiralled up and down inside ...