Drepanosaurus, Oddest Arm Ever

Drepanosaurus is one of the more unusual megalancosaurs due to the extreme development of the forelimb. Simply using this figure, the short, robust humerus, an inturned, condylar and cylindrical humeral caput articulating with the shoulder girdle, a robust and rotated distal extensor crest, the strongly expanded and nearly circular ulna, and the ulnare which is longer than the radius and possessing a distinct crest which is unique to it. Not shown are the modified digits, including a first digit with a strongly expanded claw almost the size of the ulna.