When Charles Walcott discovered the Burgess Shale deposits in British Columbia, it was this century's most significant invertebrate fossil discovery, for the Shale provides an unprecedented window into the explosive evolution during the Cambrian Period that began some 540 million years ago. Not only do the Shales contain vast numbers of fossils, but they are preserved in remarkable detail. This book provides the first comprehensive set of illustrations of fossils from the Burgess Shale, and includes a full history of its discovery and exploration. There is also a full discussion of the Cambrian radiation, the period when almost all the major phyla of animals evolved, and a complete list of all currently accepted species described from the Burgess Shale.