Scapula fragment
Flat bone; part of the limb (appendicular) skeleton.
Also known as: Shoulder blade, Wing bone, Blade bone
Classification
Flat bone; part of the limb (appendicular) skeleton.
Dimensions
In its complete form, this bone is typically broad and triangle-shaped. This specific piece is a small, thin fragment, representing just a portion of the flat, plate-like section of the shoulder.
Key Features
The most telling feature is the extreme flatness and thinness of the bone, similar to a stout autumn leaf or a piece of slate. Even in fragments, look for a slight curve across the surface and a smooth, hard outer texture that protects a very thin layer of honeycombed interior. One side is usually smooth for gliding against the ribs, while the other may have a raised ridge or 'spine' for muscle attachment.
Similar Bones
Small pieces can be confused with fragments of the skull (cranium) or the pelvic (hip) bones. You can tell them apart because skull fragments are often more curved and have distinct 'puzzle-piece' edges where they joined other bones. Pelvic fragments are usually much thicker and heavier than the delicate, wafer-thin sections of a shoulder blade.
Across Species
The shoulder blade varies wildly across the animal kingdom. In birds, it is long and narrow like a sword to support flight muscles. In four-legged runners like horses or deer, it lacks a collarbone connection, allowing the entire shoulder to slide back and forth for a longer stride. In swimming mammals like whales, it is a wide, fan-like paddle that anchors the powerful front flippers.
Evolutionary History
This bone is part of the pectoral girdle, which first appeared in ancient fish as a series of plates behind the gills. As vertebrates moved onto land, these plates evolved into sturdier supports for weight-bearing limbs. Over millions of years, the shoulder blade became larger and flatter to provide a broad surface for the complex muscles required for climbing, digging, and eventually, the sophisticated reaching motions of primates.
Photography Tips
Place the fragment on a plain, neutral background alongside a common object like a coin or ruler for size comparison. Take one photo looking straight down at the flat surface and another from the very edge to show its thickness. Good natural side-lighting will help highlight any subtle ridges or textures on the 'blade' surface.