A brief account is given of events and influences that preceded my being invited to lead the palaeobiological reinvestigation of the Burgess Shale. Joining these studies were D.L. Bruton and C.P. Hughes, subsequently D.E.G. Briggs and S. Conway Morris at Cambridge, in Oslo, and in the National Museum of Natural History, Washington, D.C. The geological setting of the Shale was first revealed by W.H. Fritz. Concomitant studies of Precambrian fossils, trace fossils, small shelly fossils of the early Cambrian, and new discoveries of soft-bodied biotas in China, Sweden and Greenland, have stimulated thought on evolutionary processes, and given rise to the concept of the Cambrian explosion.

In looking forward I comment on the importance of new investigations on taphonomy, and the promise they have for deeper understanding of what is preserved in the fossils, and of how they may be better prepared for study. The description of Anomalocaris revealed that predation by larger animals was a factor in palaeoecology from the early Cambrian onwards. Geochronology has shown the relative brevity of the Middle and Upper Cambrian, and I suggest that the transition from these times into the Ordovician may present as great a challenge in the understanding of evolutionary events as does the earlier Cambrian explosion. Despite the sporadic nature of the fossil record, new collections and new approaches give palaeontology a great opportunity to continue giving its unique contribution to the understanding of how evolution proceeded.