02 October 1998
Vol 282, Issue 5386

About The Cover

Cover image expansion

COVER Assumed worm burrows in a 1.1-billion-year-old sandstone from central India. These trace fossils extend the record of animals to twice the age of the Cambrian evolutionary explosion. The burrows (~3 to 4 millimeters wide) were probably made in a shallow sea underneath a microbially bound surface mat, and weathering of the mat layer was necessary to reveal them. See page 80. [Photo: W. K. Sacco]