Dragon skeletal anatomical diagram because I love taking on projects I and only I will enjoy. The idea is they evolved from theropod dinosaurs. Don't ask me how a tetrapod developed 6 limbs, I don't have answers for you.
Paleoheads feel free to nitpick any anatomical minutia I might have gotten wrong, I'm so here for it.
Inspired but not strictly following the dragons in the Eragon series.
Footnotes below the cut:
Fig A:
Spent a good while debating how to differentiate the naming for the forelegs and the wings, since they are technically duplicates of the same structure. I settled for "anterior" for the legs and "posterior" for the wings, but I also considered M. for "manus" referring to the legs, and A. for "ala" for the wings. ¯\_(ツ)_/¯
5. Dorsal Vertebrae 1-3 do not have dorsal spikes.
9. Dorsal spikes sprout from the spinous process and are surrounded by a kerotenous sheath. They become proportionally taller with age.
13. Anterior scapula is fused to the sternum and forms a ball-and-socket joint with the anterior humerus at the base.
14. Large keeled sternum for the attachment of flight muscles.
22. Posterior scapula is also fused to the sternum but the ball-and-socket joint is at the distal end.
36. The dracoid bone (or false finger) is a unique bone to dragons that I made up. It has a bony core and cartilaginous sheath. Inspired by the pteroid, a bone in pterosaurs, which also supports the wing membrane, but in a different location.
Fig B:
Dragons have anywhere from 46-54 teeth, but will always have 10 premaxillary teeth, four maxillary fangs (two on each side), 8 pre-fang dentary teeth, and 2 dentary fangs. The fangs slot into each other for gripping prey. Teeth are named after the bone they grow out of. Like other theropod dinosaurs, teeth are regrown throughout an individual's life.
1. Cross section of maxillary fang. Fangs are laterally compressed like blades for piercing and shearing off flesh.
4. Dragons have two maxillary fangs, with the first one being larger and visible when the mouth is closed. This "snaggle tooth" gets proportionally longer each time it regrows.
5. All dragon teeth have serrations.
6. Like T-Rex and other theropods, premaxillary teeth (and pre-fang dentary teeth) have a D-shaped cross section for delicately picking flesh from bones. Serrations are on the lateral sides and not anterior-posterior, like the fangs and post-fang teeth.
Fig C:
4. Dragons have proportionally enormous nostrils due to the high oxygen demands of flight.
8. The antoribital fenestra (and other openings in the skull) are very large in dragons to reduce the weight of the skull. This makes flight easier at the expense of bite force. While still capable of a formidable bite, it is no where near the power of a T-rex.
10. Large lacrimal bone gives the dragons their characteristic brows, and provides support for large lacrimal osteoderms.
11. Dragons have proportionally enormous eyes and excellent long-distance binocular vision.
14. Dragons horns are modified growths from the parietal bone, and thus called parietal horns. The supratemporal fenestra (holes most theropods have on the top/back of the skull) in dragons has closed to provide support for the parietal horns.
15. The parietal horn forms a bony core with a kerotenous sheath, much like their dorsal spikes (and goat horns). Grows continuously with age.
