The early rudiment of the shaft bone. A unitary developmental system.
D000818:Animals; D002642:Chick Embryo; D005360:Fibula / Q000196:embryology; D006614:Hindlimb / Q000196:embryology; D010012:Osteogenesis; D011884:Radius / Q000196:embryology; D013977:Tibia / Q000196:embryology; D014457:Ulna / Q000196:embryology; D014921:Wings, Animal / Q000196:embryology