Upper Triassic vicariance that spans the Pacific involving terrestrial biotas in south east Asia/south western North America and Queensland/Chile/Argentina is sum- marized. These terrestrial and freshwater organisms did not migrate via high-latitude landbridges or across ocean barriers or Pangaea, are endemic to these vicariant fragments, and are mostly identical species. Rejoining the vicariant fragments is compatible with rapid earth expansion but is incompatible with other geological theories that call upon Panthalassa, Pacifica, displaced terranes and slow earth expansion. Vicariance biogeography yields a rigorous test of these models since its data are derived entirely independently of them. The Upper Triassic time-frame was selected because it immediately preceded the break-up of Pangaea.