How much do we know about the anatomy and physiology of chocobos in FFXIV?

I am mostly interested in musculoskeletal structure, because from a mechanical and (quasi-) evolutionary perspective, the point where their wings attach doesn't seem to make sense - it looks like they're attached midway through the spine, or possibly at the top of the pelvis, and that they don't seem to have ample musculature to support their use.

I can forgive their flying because a wizard did it wind aether and such, but I am sorely confused by their anatomy.

Of all the magical creatures and potential anomalies in the game, he's asking about THAT?! FFS, someone get this guy a beer so he'll shut up...