The celebrated lower Cambrian Chengjiang biota of Yunnan Province, China, represents one of the most significant ever paleontological discoveries. Deposits of ancient mudstone, about 520 million years old, have yielded a spectacular variety of exquisitely preserved fossils that record the early diversification of animal life. Since the discovery of the first specimens in 1984, many thousands of fossils have been collected, exceptionally preserving not just the shells and carapaces of the a...