The sizes are small. Body length 4.1-5.7 cm. Tail length 9.3-12.6 cm. The head is relatively large. Its front part is shortened and somewhat dulled. The external auricles are small, tubular. Very long vibrissae are characteristic. The forelimbs are five-fingered, the hind limbs are three-fingered. On the sole and lower surface of the fingers of the hind limbs, a brush of hard elongated hair is highly developed. The tail has no “banner” and is covered with sparse, short hair, alternating with long hair, more numerous at its end. The proximal third or half of the tail is thickened due to fat deposits. The hairline is high, thick, soft. The dorsal side of the body is light sandy, sometimes dark yellow, and the ventral is whitish or light yellowish. Nipples 4 pairs.
In the skull, the front section is shortened, narrow. The brain capsule is trapezoidal, highly dilated, tapering anteriorly. Bone auditory drums are large, swollen, in contact with the anterior sections. The lower jaw is high, short. Number of buccal teeth4 / 3. The upper incisors on the outer surface do not have grooves.
Chromosomes in a diploid set in a fat-tailed jerboa 46. Distributed in Central Asia and southeast Kazakhstan. Ecology is poorly studied. Inhabit deserts and steppes. The fat-tailed jerboa lives in the feather-grass-wormwood sand steppes, as well as in the fixed tuberous sands. Digs up temporary simple and permanent, more complex, more than 3 m long burrows. It feeds on various plant objects and insects.
Kozlov jerboa - S. kozlovi Vinogradov, 1922 (Gobi in the MPR),
fat-tailed jerboa - S. crassicauda Vinogradov 1924 (steppes of the Dzungaria in the MPR and China, in Russia - the Zaysan depression),
jerboa of Thomas - 5. thomasi Vinogradov, 1928 (Afghanistan)
How to find out
Body length 47-50 mm. Tail length up to 106 mm. Outwardly resembles a jerboa. The base of the tail can be thickened as a result of fat deposition. The tail is covered with sparse short hair, and sparse, long bristles grow at the end of the tail.
The head is relatively large with a shortened and dull front part. The ears are small, tube-shaped. Vibrissae are very long. The forelimbs are five-fingered, hind three-fingered. On the sole of the foot, a brush of hard hair is quite well developed. The hairline is high, thick and soft. Its color on the back is light sandy, and on the belly is white or light yellow.
Lifestyle and Biology
Populate the feather grass and wormwood sandy steppes and semi-deserts, as well as the fixed hilly sands. Burrows are holes with 1–4 outlets, up to 3 m long. The nesting chamber is usually at a depth of about 50 cm in a layer of wet sand. The size of an individual plot is from 100 m2 to 4 ha. Lead a solitary lifestyle. They hibernate for the winter from November to March.
They feed on seeds and small invertebrates. Most females bring in two litters per year, in each of which there are from one to five cubs. Pregnancy and lactation for 20 days. Puberty occurs at the age of a year. Life expectancy in nature is up to three years.