The internal anatomy of the passenger pigeon has rarely been described. Robert W. Shufeldt found little to differentiate the bird's osteology from that of other pigeons when examining a male skeleton in 1914, but Julian P. Hume noted several distinct features in a more detailed 2015 description. The pigeon's particularly large breast muscles indicated a powerful flight (musculus pectoralis major for downstroke and the smaller musculus supracoracoideus for upstroke). The coracoid bone (which connects the scapula, furcula, and sternum) was large relative to the size of the bird, , with straighter shafts and more robust articular ends than in other pigeons. The furcula had a sharper V-shape and was more robust, with expanded articular ends. The scapula was long, straight, and robust, and its distal end was enlarged. The sternum was very large and robust compared to that of other pigeons; its keel was deep. The overlapping uncinate processes, which stiffen the ribcage, were very well developed. The wing bones (humerus, radius, ulna, and carpometacarpus) were short but robust compared to other pigeons. The leg bones were similar to those of other pigeons.
the internal anatomy of the passenger pigeon has rarely been described robert w shufeldt found little to differentiate the bird's osteology from that of other pigeons when examining a male skeleton in 1914 but julian p hume noted several distinct features in a more detailed 2015 description the pigeon's particularly large breast muscles indicated a powerful flight (musculus pectoralis major for downstroke and the smaller musculus supracoracoideus for upstroke) the coracoid bone (which connects the scapula furcula and sternum) was large relative to the size of the bird  with straighter shafts and more robust articular ends than in other pigeons the furcula had a sharper v-shape and was more robust with expanded articular ends the scapula was long straight and robust and its distal end was enlarged the sternum was very large and robust compared to that of other pigeons; its keel was deep the overlapping uncinate processes which stiffen the ribcage were very well developed the wing bones (humerus radius ulna and carpometacarpus) were short but robust compared to other pigeons the leg bones were similar to those of other pigeons