Rhombomys opimus (Lichtenstein 1823)

[Rhombomys] opimus (Lichtenstein 1823), Naturh. Abh. Eversmann's Reise: 122.

Type Locality: Kazakhstan, Kzyl-Ordinskaya, KaraKumy Desert (see Pavlinov and Rossolimo, 1987).

Vernacular Names: Great Gerbil.

Synonyms: Rhombomys alaschanicus Matschie 1911; Rhombomys dalversinicus Kashkarov 1926; Rhombomys fumicolor Heptner 1933; Rhombomys giganteus Buchner 1889; Rhombomys major Burdelov 1989; Rhombomys minor Burdelov 1989; Rhombomys nigrescens Satunin 1903; Rhombomys pallidus Wagner 1841; Rhombomys pevzovi Heptner 1939; Rhombomys sargadensis Heptner 1939; Rhombomys sodalis Goodwin 1939 .

Distribution: From S Mongolia and N China (Xinjiang, Gansu, Nei Mongolia) to Kazakhstan, Iran, Afghanistan, and SW Pakistan (Corbet, 1987 c, Ma et al., 1987; Wang, 2003; Zhou et al., 2000).

Conservation: IUCN – Lower Risk (lc).

Discussion: Reviewed by Pavlinov et al. (1990). Regional reviews cover Pakistan (Roberts, 1977), Iran (Lay, 1967), Afghanistan (Hassinger, 1973), Russia and adjacent regions (Gromov and Erbajeva, 1995), and N China (Xinjiang, Gansu, and Nei Mongolia; Ma et al., 1987; Zhang et al., 1997; Zhou et al., 2000). Rhombomys opimus is unique among gerbils in having hypsodont, evergrowing (rootless) molars with cement in the reentrant angles, but Pavlinov (1982 b, 1996) found a few old individuals with rooted molars from several localities in Iran; however, this discovery does not help clarify taxonomic status of the species. Chromosomal data summarized by Qumsiyeh and Schlitter (1991). Morphology and schmelzmuster of rootless molars in relation to jaw motion documented by Koenigswald et al. (1994) and compared to 24 other extant rodent genera. Phallic morphology described by Yang et al. (1992). Age identification and population structure of Chinese population reported by Zhou et al. (2002), who also mapped the nine different dry habitats in N China occupied by R. opimus, noting that its distribution has been altered there through human activities.