The Burgess Shale is probably the world's most famous lagerstätte (site of special preservation). Discovered in 1909 on Mt. Stephen, in the Canadian Rockies of British Colombia, Canada, this locality provided an early representation of the true biodiversity of the Cambrian Period. For decades, discoveries from this site have helped palaeontologists better understand the 'Cambrian Explosion' and the origins of modern lineages. Since that time, many more early lagerstätten have been discovered, so we asked Prof. Simon Conway Morris, from the University of Cambridge, if this well-studied locality still holds its relevance to modern palaeontology.