09 November 2012
Vol 338, Issue 6108

About The Cover

Cover image expansion

COVER Masks on the facade of the Codz Poop Palace (Kabah site, Yucatan, Mexico). Kabah and other Maya sites in the Puuc region flourished during the Terminal Classic Period (800 to 1000 C.E.), while cities to the south collapsed as the climate became drier. Political collapse was part of a complex two-stage societal response to global climate change. See page 788. Photo: Getty Images/DEA/G. Dagli Orti