The single species, S. betpakdalaensis, occurs in deserts to the west and north of Lake Balkhash in eastern Kazakhstan (Corbet 1978, 1984). There is a short but confusing taxonomic and nomenclatural history centering on Selevinia (see Arata 1967). The genus originally was placed in the Muridae, then was considered by various authorities to represent either a subfamily of the Myoxidae or an entirely separate family, and finally was placed by Holden (in Wilson and Reeder 1993) in the myoxid subfamily Leithiinae and regarded as a relative of Myomimus. The only known fossils that may have close affinity to Selevinia are two mandibles from the Pliocene of Poland (Klingener 1984).
Head and body length is 75-95 mm and tail length is 58-77 mm (Ognev 1963). Two pregnant females weighed 21.4 and 24 grams, and a small male weighed I8 grams. The dense fur is grayish above and whitish below. The method of molt is peculiar: instead of a sloughing off of individual hairs, the epidermis becomes detached along with the hairs growing on it. A dense growth of new hair is found already in place in areas where patches of skin have fallen off. The molt begins at the back of the neck (between the ears) and then proceeds along the back and sides; the entire process takes about a month. The new hairs come in quickly, growing up to I mm in a 24-hour period. In winter the individual hairs attain a length of 10 mm. The tail is covered with short hairs, and the scales are not visible. The palms and soles are naked.
It has been suggested that Selevinia is a highly modified and aberrant dormouse, it has a round, stocky body and a long tail. The hand has four digits and the foot has five. The external ears extend beyond the fur. The skull has enormous tympanic bullae and relatively weak zygomatic arches. The dental formula is usually given as: (i 1/1, c 0/0, pm 0/0, m 3/3) x 2 = 16; however, there are also two upper premolars that are lost early in life (Klingener 1984). The upper incisor teeth are massive and have a deep groove on their front surface. The small, single-rooted cheek teeth have a relatively simple enamel pattern.
Selevinia has a sporadic distribution in clay and sandy deserts. It occurs among thickets of Spirianthus, in growths of wormwood, and among boyalych (Salsola laricifolia). It may live in burrows under the bushes, but a captive dug a burrow (28 cm long) only when the temperature was low, sheltering at other times under a leaf or small stone. Some observers have reported Selevinia to be diurnal, but most individuals come out at twilight and remain active throughout the night, thus avoiding the heat. When the captive mentioned above was brought out into the sunlight for five minutes at midday in March, its ear muscles were so badly burned that it almost died.
When undisturbed the desert dormouse travels at a leisurely, ambling gait, but when alarmed it progresses by small leaps. It does not jump higher than about 20 cm but is a good climber. It is quite active at moderate temperatures, when it may venture far from its shelter. Signs of its presence are not extensive in a given area, and there have been suggestions that it leads a nomadic life in the summer. When temperatures fall below about 5' C, however, Selevinia goes into a state of dormancy, during which its breathing rate may decrease from 108 to 25 per minute. Although such behavior has been observed only in captivity, it is reasonable to assume that it takes place in nature. Such a period of lethargy might explain the apparent scarcity of Selevinia during the colder parts of the year.
The diet seems to consist solely of invertebrates such as insects and spiders. The intestinal tracts of insects, at least of mealworms, are not eaten. Selevinia eats as much as three-fourths of its weight in a 24-hour period. About one-fourth of the insect food eaten by a captive was discharged as feces, mostly in the form of indigestible chitinous material. Selevinia readily drinks water in captivity.
The desert dormouse is quite gentle in captivity. It does not attempt to bite when caught and held in the hand. Peculiar chirping sounds are emitted when it is feeding or disturbed. Mating takes place in May and possibly again in July. Pregnant females with six or eight embryos have been reported.
Selevinia appears to be rare but is seen from time to time. llchenko and Volodin (1992) reported the collection of a single specimen during surveys in June 1988 and May-June 1989. The IUCN now classifies the genus as endangered because of its evidently restricted and declining habitat.
Information taken from: Nowak, R.M. (Ed.). Walker's Mammals of the World. 6th Edition. The John Hopkins University Press. Baltimore and London, 1999.