carpometacarpus – a bone in the wing of a bird formed by the fusion of bones between the wrist and the knuckles

furcula – The wishbone, or forked clavicle, that stabilizes a bird’s shoulders

keel – An extension of the sternum (breastbone). It provides an anchor to which a bird’s wing muscles attach, and provides adequate leverage for flight.

pygostyle – A triangular plate formed of the fused caudal (tail) vertebrae, typically supporting the tail feathers

quill knobs – Sites on the bone where large feathers attach

skeletal pneumaticity – The presence of air spaces within bones

synsacrum – Elongated composite sacrum (structure at the base of the spine) containing a number of fused vertebrae

tarsometatarsus – a compound bone in the foot of a bird formed by the fusion of some bones of the upper and lower foot

tibiotarsus – a bone in the leg of a bird formed by the fusion of the tibia and some bones of the upper foot

uncinate process – A protrusion of bone from a rib, enabling it to join on to the rib behind by means of ligaments. It is an avian feature that serves to strengthen the rib-cage.