A furcula is the technical name for a bird's wishbone, that Y-shaped bone you might pull apart at Thanksgiving dinner.

The furcula is actually two collarbones that have fused together during a bird's development. It works like a spring, storing and releasing energy when a bird flaps its wings, helping make flight more efficient. Without this special bone, birds would have to work much harder to stay airborne.

Scientists have discovered that many dinosaurs also had furculae, which is one piece of evidence that birds evolved from certain dinosaur species. When paleontologists find a furcula in a dinosaur fossil, it tells them something important about that creature's anatomy and its relationship to modern birds.

While most people just call it a wishbone and think about making wishes, ornithologists (scientists who study birds) use the term furcula when discussing bird anatomy. The bone's strength and flexibility vary between different bird species. A hummingbird's furcula looks very different from an eagle's because each bird has different flying needs.