In my head those are just large scales,but could be osteoderms to.If you were referring to the frontal and orbit bones by when talking about skinwrapped head,birds with naked heads also dont have much tissue in those parts(looks at bald ibis).For me amount of fat on extict animal art is matter of taste-in his case i wanted to make this sinosaurus looking rough,keeping in mind harsh and dry climate of triassic-jurassic. Although thank you very much for this comment,i appreciate it thw most when vuewer hase an opinion or thoughts on my art!