Vertebra
Irregular Bone and part of the axial skeleton (the core framework of the body).
Also known as: Backbone, spinal segment, or link in the spine.
Classification
Irregular Bone and part of the axial skeleton (the core framework of the body).
Dimensions
Typically chunky and blocky, these bones vary in size from small pebbles in garden birds to large, heavy blocks the size of a loaf of bread in large mammals. They are generally as wide as they are tall.
Key Features
Look for a central thick body that resembles a spool or drum, with various wings and spikes branching out. There is usually a large central hole or a deep arch where the spinal cord once rested. The surfaces where they touch their neighbors are often smooth and flat or slightly cupped.
Similar Bones
Broken pieces of the pelvis can sometimes look like vertebrae because of their irregular shapes, but pelvic bones are usually flatter and lack the central round drum-like body. Parts of the skull base can also be confusing, but they typically have more complex small holes and thinner walls.
Across Species
Across the animal kingdom, the backbone is a masterpiece of engineering. In birds, some of these bones are fused together to provide a rigid platform for flight, while in snakes, they are numerous and highly flexible to allow for slithering. In large mammals like cows or deer, the top spines of the vertebrae in the shoulder area are often very long to provide attachment points for powerful neck muscles.
Evolutionary History
The backbone is the hallmark of the vertebrates. It evolved from a simple flexible rod called a notochord seen in early sea creatures into a series of interlocking bony segments. This transformation allowed animals to support their weight on land, protect the central nerve cord, and develop complex movements like running, jumping, and swimming.
Photography Tips
Place the bone on a plain background. Capture one photo looking straight through the central hole, and another from the side to show the height of the bony spikes. Including a coin or a ruler nearby is essential to show the scale for identification.