I have been studying muscles lately and i've come with this dragon anatomy study, it was really hard to do, specially putting an extra limb(wings) there..
I used a lot of references:
-"Animal Antomy for Artists" from Eliot Goldfinger;
- Terryl Whitlatch dinosaur and lizard anatomy sheets from her Creature Anatomy course;
-and some photos.
Feel free to critique it, I will love to see your points.
Update: Changed the wings; See the older version here:
for the tips/suggestions!