The dark meat of the chicken is from the legs, drums and the thighs. This meat is darker because when muscles are more heavily worked, they hold more oxygen, which gives the meat a red color.
The USDA grades chicken on appearance, not fat content. Grade A means the chicken is well formed, free of feathers and has unblemished skin. The same is true for turkey.
Varieties of poultry dark meat include drumsticks, thighs, boneless skinless thighs and leg quarters.