Archaeopteryx perhaps, to a cartilaginous sternum. The sideways orientation of the glenoid (shoulder) joint between scapula, coracoid, and humerus—instead of the dorsally angled arrangement found in modern birds—may indicate that "Archaeopteryx" was unable to lift its wings above its back, a requirement for the upstroke found in modern flapping flight. According to a study by Philip Senter in 2006, "Archaeopteryx" was indeed unable to use flapping flight as modern birds do, but it may well have used a downstroke-only flap-assisted gliding technique. "Archaeopteryx" wings were relatively large, which would have resulted in a low stall speed and reduced turning radius. The
Specimens of Archaeopteryx other "Archaeopteryx" specimens. The left wing preserves the better plumage and shows flight feathers firmly connected to the arms. Though the wings overlap each other enough that assigning feather attachment points to individual bone regions is not possible, it does appear, consistent with other specimens and modern relatives, that the long primary feathers are attached to the second manual digit. The feathers of the right wing are considerably more damaged; so many feathers are missing that only a few can be definitively linked to the ulna, designating them as secondary remiges. One small feather is isolated next to the right