Furcula
Irregular Bone, part of the appendicular skeleton
Also known as: Wishbone
Classification
Irregular Bone, part of the appendicular skeleton
Dimensions
Varies widely from tiny fractions of an inch in small songbirds to several inches across in larger waterfowl and raptors, forming a characteristic V or U shape.
Key Features
A symmetrical V-shaped or U-shaped structure formed by two slender arms meeting at a fused bottom tip, often featuring a small flat plate or tiny bony projection at the bottom center point.
Similar Bones
Can sometimes be confused with paired slender collarbones of other animals or tiny jaw fragments, but the fused V-shape and springy symmetry are uniquely characteristic of avian flight anatomy.
Across Species
Found exclusively in birds and their dinosaur ancestors. In heavy-chested or soaring birds like geese and eagles, it acts as a resilient spring to store energy during the wing-down stroke. In flightless birds like ostriches, the bone is reduced or missing entirely since they do not need the aerodynamic bracing.
Evolutionary History
The wishbone is a gift from the dinosaurs, shared by meat-eating theropods long before the first true birds took to the sky. Over millions of years, the paired collarbones fused into a single elastic spring, helping early flying creatures handle the tremendous muscle stresses of powered flight.
Photography Tips
Place the bone on a solid, contrasting background. Take a top-down, flat-lay shot to capture the full V-shape clearly, and include a small coin or ruler next to it for scale.