Figure 1. Period of human–megafauna overlap and climate variation in Sahul.

(a) Distribution of extinction times for all megafauna genera with a model agreement >50% (grey barplot, left y-axis) and distribution of the percentage of model agreement to infer the time of first human occurrence (blue barplot, right y-axis). Marine isotope stages (MISs) 1 to 5 (ref. ²⁶) are shown across the top axis for temporal reference. (b) Percentage agreement between six models¹⁷ used to infer both the time of extinction for each megafauna taxon (black=100% model agreement, grey=50% and white=0% agreement) and the time of first human occurence (from dark blue=100% agreement to white=0% agreement) from fossil and archaeological records. For each taxon, crosses and grey lines denote fossil ages and their 2σ uncertainties; the red crosses and lines show the most recent fossil ages and their 2σ uncertainties. The cutoff at 50% is the maximum threshold to compute an extinction window for each taxon. (c) Frequency distribution of the youngest age for each genus of all 16 genera (red plot), accounting for dating uncertainties, and temporal range of first human occurrence (black line) established from ages±2σ uncertainties of the oldest archaeological evidence rated as high quality. (d) Mean annual temperature anomalies relative to the present day (±s.d., grey-shaded envelop), calculated from the Antarctica EPICA Dome C ice core²² and corrected for time-resolution sampling bias. (e) Mean annual temperature and (f) precipitation anomalies relative to the present day in Sahul, calculated from HadCM3 palaeoclimate simulations⁴⁷. (g) Variation in ENSOp (dimensionless) estimated from the Zebiak–Cane coupled ocean–atmosphere model forced only by changing orbital parameters²³. (h) Velocity of climate change³⁴ calculated from mean annual temperature (dark grey) and precipitation (light grey) in e and f, respectively. In e, f and h, the time resolution of each variable is standardized using a 4 kyr running mean starting 80 kyr ago; the bold lines indicate the median value, whereas the lower and upper limits of their grey-shaded envelopes are determined by the first and third quantiles, respectively.