Figure 3.

The evolution of key vertebrate clades, showing diversification shifts. Clades are collapsed to 47 representative stem lineages and coloured by extant species diversity. Clades with unusual diversification rates are denoted with numbers; yellow and blue squares denote diverse and impoverished clades, respectively, compared with background rates of evolution. The impoverished clades (numbers 3, 6, 5; sarcopterygian fishes, rhynchocephalians, crocodiles) are classic ‘living fossils’, whereas the speciose clades (numbers 8, 2, 1, 7, 9, 4) shows expansions of diversity clustered in the time from 150 to 100 Ma. From [33]. (Online version in colour.)