... southwestern Australia 150,000 390,000 Chihuahuan Mexico/southwestern United States 140 ,000 360,000 Takla Makan northern China 140 ,000 360,000 Sonoran Mexico/southwestern United States 120,000 310,000 *These ... northern Africa 3,500,000 9,065,000 Gobi Mongolia/northeastern China 500,000 1,290,000 Patagonian Argentina 260,000 670,000 Rub al Khali southern Arabian Peninsula 250,000 650,000 Great Sandy northwestern...