11 November 2005
Vol 310, Issue 5750

About The Cover

Cover image expansion

COVER Fossil leaf from the earliest Eocene (~55.5 million years ago) of the Bighorn Basin, Wyoming. The beginning of the Eocene was characterized by rapid global warming after a huge release of carbon into the atmosphere and ocean. Plant fossils described on page 993 document rapid, continental-scale changes in the geographic ranges of plants coincident with the warming. [Photo: S. Wing]