Fig. 3.

Groups terminating at one of the ‟big five” mass extinction events (and living groups that are still diversifying) are more top-heavy than those terminating at other times. (Left) Disparity profile frequencies for extinct clades that do not terminate at a mass extinction boundary. (Center) Disparity profile frequencies for extinct clades that terminate at a mass extinction boundary. (Right) Disparity profile frequencies for living clades (truncated by the Recent). Bars to the left and right of the dotted lines indicate the frequencies of bottom-heavy (CG <0.5) and top-heavy (CG >0.5) clades, respectively. Black bars indicate the frequencies of significantly bottom- or top-heavy clades (P < 0.05), while gray bars indicate the frequencies of clades for which P ≥ 0.05. Mass extinctions: Late Ordovician, 443.7 Ma; Late Devonian, 374.5 Ma; Late Permian, 251 Ma; Late Triassic, 199.6 Ma; and Late Cretaceous, 65.5 Ma.