09 September 1994
Vol 265, Issue 5178

About The Cover

Hominid hand bones from Swartkrans Cave, South Africa. Comparative anatomy of the thumb, from Paranthropus robustus (about 1.8 million years ago), shows that this hominid could use tools. Other hominids found along with tools in deposits younger than 2.5 million years ago also evidently could use tools, but hominids that predate the appearance of tools lack the anatomical hallmarks of tool use. See page 1570 and the Perspective on page 1540. [Photo: Randall L. Susman]