Long bone length is stimulated by the production of growth hormone (GH), a secretion of the anterior lobe of the pituitary gland. The long bone includes the femora, tibiae, and fibulae of the legs; the humeri, radii, and ulnae of the arms; metacarpals and metatarsals of the hands and feet, the phalanges of the fingers and toes, and the clavicles or collar bones. The long bones of the human leg comprise nearly half of adult height. The other primary skeletal component of height are the vertebrae and skull. The outside of the bone consists of a layer of connective tissue called the
Ostromia addition, the ungual (claw) of the first digit of the hand is smaller than the corresponding first metacarpal, while in "Archaeopteryx" the claw is larger. The Haarlem specimen's metatarsals are also estimated to be proportionally longer than those of "Archaeopteryx" specimens. In addition, the Haarlem specimen shares several features with "Anchiornis". Most notably, they both have longitudinal furrows on the top and bottom sides of their manual phalanges (finger bones). While such structures can be a result of collapsed or broken bones (as is the case in several "Archaeopteryx" specimens), the straight, smooth edges of the furrows in "Ostromia" and