Gobi jerboa by the Central Asiatic Expeditions and housed at the American Museum of Natural History (Allen 1925). Allen further compared the subspecies "Allactaga sibirica annulata" and "Allactaga sibirica sibirica", to the Gobi jerboa because they are all sympatric. Allen examined forty specimens collected from different regions of Mongolia, and found that while the Gobi jerboa was similar in color and appearance to "A. sibirica annulata", by exhibiting the same grayer and buffier phases, the Gobi jerboa has shorter and broader ears, smaller hind feet, and a much larger globular audital bullae (nearly three times the size), which differentiates it from "A.
Gobi Desert is a rain shadow desert, formed by the Tibetan Plateau blocking precipitation from the Indian Ocean reaching the Gobi territory. The Gobi measures over from southwest to northeast and from north to south. The desert is widest in the west, along the line joining the Lake Bosten and the Lop Nor (87°–89° east). It occupies an arc of land in area as of 2007; it is the fifth-largest desert in the world and Asia's second largest. Much of the Gobi is not sandy but has exposed bare rock. In its broadest definition, the Gobi includes the long stretch of desert