As a result of pronation of the forelimb in the spread wing the peaks
of the digital claws am orientated backwards. The 6th (Solnhofen) spec
imen of Archaeopteryx demonstrates that its digital claws were orienta
ted in the same way. Given is an interpretation of the position of the
claws of Berlin and Eichstatt specimen. Shown are the consequences fo
r theories of origin of birds' flight, functions of the digital claws
and other problems.