Abstract
In 1909, Charles Walcott, a well-known scientist, discovered a most unusual Middle Cambrian fossil site about 3500 ft above Emerald lake in Yoho National Park, British Columbia, Canada. During several summers of work, he and his assistants extracted thousands of fossils that served as a basis for several scientific papers. In the last twenty years, renewed research on these fossils has been conducted by several paleontologists, including Harry B. Whittington of Cambridge University and two of his students, Simon Conway Morris and Derek Briggs. Their careful work has revealed a spectacular army of unusual animals so different from any that now exist that more than a dozen new phyla have been erected to classify them. Walcott's quarry has now been declared a "world heritage" site and no collecting is permitted. Indeed, no one may visit the site without an accompanying park warden.