First, the great profusion of completely novel forms of life in the Burgess assemblage (feature 3) demanded even more transitional forms than had previously been thought missing. Each new and exotic Cambrian creature—the anomalocarids (see Fig. 2.10), Marrella, Opabinia, and the bizarre and appropriately named Hallucigenia—for which there were again no obvious ancestral forms in the lower strata, required its own series of transitional ancestors. But where were they?
