Jerboas were the characteristic group of rodents of the Old World lived in open spaces. In ice age at the boundary of Holocene and Neocene, in conditions of desertification and deforestation, some representatives of jerboa family had got a wide distribution and had considerably increased in size. This adaptation, favourable in conditions of cold climate, has allowed one species of these rodents to occupy an ecological niche of the analogue of small antelopes in steppes of Eurasia. This animal is giant kangaroo jerboa, a gregarious middle-sized mammal. This rodent has kept features of anatomy, characteristic for family representatives, adjusted for the giant size: the animal weighs up to 15 kg. In behaviour and a habit of movement giant kangaroo jerboa is similar to small kangaroos like wal