Contents

02 April 2004
Vol 304, Issue 5667

About The Cover

Cover image expansion

COVER Reconstructing the posture of an extinct animal from isolated bones. The humerus of a Devonian tetrapod, found in Pennsylvania, shows that it could support the front end of its body in a low, wide stance. This posture reflects an intermediate stage in the evolution of amphibian limbs from fish fins. See page 90. [Art by Kalliopi Monoyios]