22 November 1996
Vol 274, Issue 5291

About The Cover

Cretaceous-Tertiary (K-T) boundary near the town of Zumaya, Spain. The boundary occurs immediately below the ledge (lower center) formed by the erosion-resistant Tertiary strata. The boulders in the foreground lie in the pre-K-T gap. Statistical analysis of the fossil distributions in this and other Bay of Biscay sections reveals a complex of extinction patterns in the latest Cretaceous. See 1360 and the News story on 1303. [Photo: Peter D. Ward, University of Washington]