Contents

24 May 2013
Vol 340, Issue 6135

About The Cover

Cover image expansion

COVER A Classopollis meyeriana conifer pollen grain (~30 micrometers across) preserved in lake sediments deposited just after a massive, volcano-induced extinction event ~200 million years ago. This fossilized pollen grain is representative of the low-diversity plant assemblages found within the tropics of the Pangean supercontinent during the postextinction recovery period. See page 941. Image: Dee Breger and Sarah Fowell/Science Source