A stylised bird skeleton
1. Skull, 2. Cervical vertebrae, 3. Furcula, 4. Coracoid, 5. Uncinate process, 6. Keel, 7. Patella, 8. Tarsometatarsus, 9. Digits, 10. Tibiotarsus (10 and 11), 11. Tibiotarsus (10 and 11), 12. Femur, 13. Pubis (innominate bone), 14. Ischium (innominate bone), 15. Illium (innominate bone), 16. Caudal vertebrae, 17. Pygostyle, 18. Synsacrum, 19. Scapula, 20. Lumbar vertebrae, 21. Humerus, 22. Ulna, 23. Radius, 24. Carpus, 25. 3rd digit, 26. 2nd digit, 27. Alula (1st digit).<br>Note: identification of bird digits as 1, 2, 3 or 2, 3, 4 is an unclear long-standing question (see, for example, <a href="https://en.wikipedia.org/wiki/Digital_object_identifier" class="extiw" title="w:Digital object identifier">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1002%2Fdvdy.22595">10.1002/dvdy.22595</a>)
<ul><li><a href="//commons.wikimedia.org/wiki/File:Squelette_oiseau.JPG" title="File:Squelette oiseau.JPG">Squelette_oiseau.JPG</a>: BIODIDAC</li>
<li>derivative work: <a href="//commons.wikimedia.org/wiki/User:Mario_modesto" title="User:Mario modesto">mario modesto</a> (<a href="//commons.wikimedia.org/wiki/User_talk:Mario_modesto" title="User talk:Mario modesto"><span class="signature-talk">talk</span></a>)</li></ul>
CC BY 2.5
<ul><li><a href="//commons.wikimedia.org/wiki/File:Squelette_oiseau.JPG" title="File:Squelette oiseau.JPG">Squelette_oiseau.JPG</a></li></ul>