Fig. 1: Four continental configurations (A–D) tested here, overlain with the palaeotopography and palaeobathymetry used in our FOAM simulations.

Configuration A: 510 Ma reconstruction, after refs. 25,26,27. Configuration B: terminal Ediacaran–early Cambrian reconstruction, after refs. 18,19. Configuration C: 510 Ma reconstruction, after refs. 30,31. Configuration D: Cambrian reconstruction, after ref. 28. A: Avalonia; B: Baltica; EG: East Gondwana; L: Laurentia; NC: North China; S: Siberia; SC: South China; WG: West Gondwana; asl: above sea level.