Furcula
Irregular bone, part of the appendicular skeleton
Also known as: Wishbone, Merrythought
Classification
Irregular bone, part of the appendicular skeleton
Dimensions
Varies widely from tiny fractions of an inch in small hummingbirds to several inches across in larger fowl like turkeys and geese, forming a characteristic V or U shape with springy proportions.
Key Features
Look for a distinct V-shape or U-shape made of two slender, curving arms joined at a central bony plate called the hypocleideum. The bone feels remarkably lightweight yet springy to the touch.
Similar Bones
Can sometimes be mistaken for small curved ribs or fragments of pelvic girdles, but the symmetrical V-shape and springy, flattened branches of the wishbone are a dead giveaway for avian remains.
Across Species
Found in birds and some feathered dinosaurs, this springy structure acts like a natural rubber band during flight. In heavy flightless birds like ostriches, it can be reduced or absent, while in powerful flyers like albatrosses and swifts, it is robust and tightly braced to handle immense wing-flapping stresses.
Evolutionary History
The wishbone is actually a fused pair of collarbones inherited directly from ancient theropod dinosaurs. Long before birds took to the skies, their meat-eating dinosaur ancestors possessed this fused chest structure, which slowly adapted over millions of years to store and release energy during active flapping flight.
Photography Tips
Lay the bone flat against a neutral, solid-colored background with a coin or ruler next to it for scale. Take one shot from directly overhead to show the complete V-shape, and a second angled shot from the side to highlight the thickness and curve of the central junction.