Gerbillus Desmarest 1804

Gerbillus Desmarest 1804, Tabl. Meth. Hist. Nat., in: Nouv. Dict. Hist. Nat., Vol. 24: 22.

Type Species: Gerbillus aegyptius Desmarest 1804

Synonyms: Endecapleura Lataste 1882; Monodia Heim de Balsac 1943 .

Species and subspecies: 38 species in 2 subgenera:

Subgenus Gerbillus (Gerbillus) Desmarest 1804

Subgenus Gerbillus (Hendecapleura) Lataste 1894

Species Gerbillus (Gerbillus) acticola Thomas 1918

Species Gerbillus (Gerbillus) agag Thomas 1903

Species Gerbillus (Hendecapleura) amoenus de Winton 1902

Species Gerbillus (Gerbillus) andersoni de Winton 1902

Species Gerbillus (Gerbillus) aquilus Schlitter and Setzer 1972

Species Gerbillus (Hendecapleura) brockmani Thomas 1910

Species Gerbillus burtoni F. Cuvier 1838

Species Gerbillus (Gerbillus) cheesmani Thomas 1919

Species Gerbillus (Gerbillus) dongolanus Heuglin 1877

Species Gerbillus (Gerbillus) dunni Thomas 1904

Species Gerbillus (Hendecapleura) famulus Yerbury and Thomas 1895

Species Gerbillus (Gerbillus) floweri Thomas 1919

Species Gerbillus (Hendecapleura) garamantis Lataste 1881

Species Gerbillus (Gerbillus) gerbillus (Olivier 1801)

Species Gerbillus (Gerbillus) gleadowi Murray 1886

Species Gerbillus (Hendecapleura) grobbeni Klaptocz 1909

Species Gerbillus (Hendecapleura) henleyi de Winton 1903

Species Gerbillus (Gerbillus) hesperinus Cabrera 1936

Species Gerbillus (Gerbillus) hoogstraali Lay 1975

Species Gerbillus (Gerbillus) latastei Thomas and Trouessart 1903

Species Gerbillus mauritaniae Heim de Balsac 1943

Species Gerbillus (Hendecapleura) mesopotamiae Harrison 1956

Species Gerbillus (Hendecapleura) muriculus Thomas and Hinton 1923

Species Gerbillus (Gerbillus) nancillus Thomas and Hinton 1923

Species Gerbillus (Hendecapleura) nanus Blanford 1875

Species Gerbillus (Gerbillus) nigeriae Thomas and Hinton 1920

Species Gerbillus (Gerbillus) occiduus Lay 1975

Species Gerbillus (Gerbillus) perpallidus Setzer 1958

Species Gerbillus (Hendecapleura) poecilops Yerbury and Thomas 1895

Species Gerbillus (Hendecapleura) principulus Thomas and Hinton 1923

Species Gerbillus (Gerbillus) pulvinatus Rhoads 1896

Species Gerbillus (Hendecapleura) pusillus Peters 1879

Species Gerbillus (Gerbillus) pyramidum (Geoffroy 1803)

Species Gerbillus (Gerbillus) rosalinda St. Leger 1929

Species Gerbillus (Hendecapleura) syrticus Misonne 1974

Species Gerbillus (Gerbillus) tarabuli Thomas 1902

Species Gerbillus (Hendecapleura) vivax Thomas 1902

Species Gerbillus (Hendecapleura) watersi de Winton 1901

Discussion: Tribe Gerbillini, Subtribe Gerbillina . Gerbillus has never been adequately revised. Lay (1983) summarized taxonomic difficulties attendant with determining if the genus was monophyletic, discussed significant character complexes that would bear on any scheme to separate species into subgenera (nature of plantar surfaces, size of auditory bulla, relative tail length, dental traits, accessory tympanum, and karyotype), provided an annotated checklist of the species he considered valid, and a list of named forms with literature citations and type localities (including geographic coordinates). Lack of concordance among the suites of characters discouraged Lay from allocating species to higher categories conventionally recognized as either subgenera or genera (see Pavlinov et al., 1990, for example), and he felt compelled to recognize a single genus without subgenera until the group was systematically re-evaluated. Several taxonomic revisions, pertinent faunal stuides (referred to in the accounts of species), reviews, and the important monograph by Pavlinov et al. (1990) have emerged since 1983; these in combination with our study of specimens and Lay's taxonomic overview form the basis for our summary, which can be viewed as a working hypothesis of specific diversity in Gerbillus . In extracting the species usually associated with Dipodillus, we follow Pavlinov et al. (1990) and Pavlinov (2001) in recognizing those species as a separate cluster ( Dipodillus) related to species of Gerbillus and depart from Lay’s arrangement. Pavlinov (in litt., 2002), however, stressed that " Dipodillus and Gerbillus could be both paraphyletic and the subgenera in each of them are certainly grades and not clades." Within Gerbillus, our listing of species under subgenera Gerbillus or Hendecapleura generally echos the treatments by Pavlinov et al. (1990) and F. Petter (1975 b).

An excellent account of species occurring east of the Euphrates River was provided by Lay and Nadler (1975). The distribution of six species endemic to North Africa was mapped and discussed by Cheylan (1990) in the context of assessing endemism and speciation of Mediterranean mammals. Tranier and Julien-Laferriere (1990) commented on suggested identities of several species from North Africa. Qumsiyeh and Schlitter (1991) summarized chromosomal data; subsequent documentation of chromosomal complements and their significance to reconstructing phylogenetic relationships among species of Gerbillus will be found in some of the references cited in various accounts of species. A contribution to allozymic variation within and between species was offered by Nevo (1982). Evolutionary tendencies within Gerbillus, as reflected in dental traits, were discussed by F. Petter (1973 c), and significance of variation in incisor microstructure within the genus was reported by Flynn (1982 c). Species of Gerbillus were included by Bonhomme et al. (1985) and Pascale et al. (1990) in their assessment of phylogenetic relationships among muroid rodents with electrophoretic and DNA-sequence data. Volobouev et al. (1995 b:258) characterized and isolated two repeated DNA sequences in G. nigeriae, G. aureus, and G. nanus and pointed out that "... in Gerbillus species, chromosomal evolution involves rearrangements of both repeated sequences and other chromosomal structures." Osborn and Helmy (1980) provided clear morphological comparisons among species of Gerbillus occurring in Egypt. Granjon et al. (2002 a) pointed out that seven species of Gerbillus ( G. cf nancillus, G. henleyi, G. nanus, G. gerbillus, G. nigeriae, G. tarabuli, and G. cf pyramidum) and two of Dipodillus ( D. campestris and D. rupicola) can be unambiguously identified in the West African Subsaharan sahelian region between southeastern Mauritania, northern Mali, and western Niger.

Evolutionary history as documented by fossils dates to early Pleistocene of China (Lucas, 2001), late Pleistocene of C India (Patnaik, 1995) and middle Pliocene to early Pleistocene of Africa (Denys, 1989 b, 1999; Tong, 1989; Wesselman, 1984; Wessels, 1998). The earliest member of Gerbillini and relative of Gerbillus is Debruijnimys from early Pliocene of Spain and late Pliocene of North Africa (Castillo and Agustí, 1996; Wessels, 1998).