FIGURE 2. Temporal patterns of mammalian diversification.

a, Lineages-through-time plot for all (blue), placental (green) and marsupial (orange) mammals. Filled circles indicate when resolution in the phylogeny dropped below 85%. b, Net diversification rates: stepped line, rate in each age or sub-epoch; solid blue curve, rate inferred from a GAM of rate against time (²  =  241.5, estimated degrees of freedom  =  14.75, P  0.001, adjusted R²  =  77.6%, deviance explained  =  20.3%); dashed curves, 95% confidence intervals. c, Counts of mammalian genera in each sub-epoch (Late Triassic to Late Eocene) according to the Unitaxon database (based on ref. 42). Red and blue lines represent genera whose families diversified predominantly before or after the Palaeocene/Eocene boundary, respectively. Throughout, the red vertical line is the K/T boundary and grey lines separate Cenozoic epochs.