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
Archaeopteryx are limited to a sort of "proto-down" not dissimilar to that found in the dinosaur "Sinosauropteryx": decomposed and fluffy, and possibly even appearing more like fur than feathers in life (although not in their microscopic structure). These occur on the remainder of the body—although some feathers did not fossilize and others were obliterated during preparation, leaving bare patches on specimens—and the lower neck. There is no indication of feathering on the upper neck and head. While these conceivably may have been nude, this may still be an artefact of preservation. It appears that most "Archaeopteryx" specimens became embedded in anoxic