Figure 1. The possible evolutionary relationships between the annelids, brachiopods, and molluscs, with the proposed position of the halkieriids and Wiwaxia. (Fig. 83 and caption from The Crucible of Creation).
Figure 2. Various interpretations of the history of life and its disparity. (a) The traditional view whereby disparity steadily increases through geologic time. (b) The view presented by S.J. Gould, whereby maximum disparity is in the cambrian. (c) The view that disparity increased rapidly in the Cambrian and thereafter stayed much the same. (d) The view presented here. Disparity increased rapidly in the Cambrian, and thereafter has generally increased, albeit at varying rates. (Fig. 88 and caption from The Crucible of Creation).