Fig. 4: FOAM GCM simulations of early Cambrian sea-surface temperatures for each continental configuration (A–D) with present-day orbital parameters.

a Maps of simulated SST for configurations A–D at 32 PAL pCO2. b Zonally averaged model (dark blue) SST annual mean and seasonal variation for each configuration and pCO2 forcing, with comparable present-day SST values (grey) from ref. 72, and lethal temperature limit for animals of 41 °C, following ref. 50, plotted with mean zonal sea-ice cover (light blue). The sea ice cover represents the percentage of the ocean that is covered by sea ice (yearly average). pCO2 levels relative to PAL (=280 ppm).