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.
Ordos Desert in the south. The Ordos Desert is almost completely encircled by the Great Bend (Ordos Loop) of the Yellow River in the west, north, and east. Mountain ranges separate the Ordos from the Gobi Desert north and east of the Yellow River. The northern border serves as the southern border of the Muu-us Sandyland. The mountain chains separating the Ordos from the central Gobi in the north of the great bend of the Yellow River are: the Kara-naryn-ula, the Sheitenula, and the Yin Mountains, which link on to the south end of the Greater Khingan Mountains. In the south and