are often mistaken for the lower legs. This gives birds their distinct—and misleading—"backward-facing knee" look. Like its non-flying close relatives, Microraptor had elongated bones lining ...

While its wings are largely useless in the air, its powerful legs make it a ground-based ... (154 pounds)—making it the largest flying bird to ever exist. Scientists believe it flew much like ...

and leg muscles rich with blood vessels to provide them with oxygen and endurance for walking. Because their chest muscles are used less than other flying birds, like ducks, they have more white ...