Acomys I. Geoffroy 1838

Acomys I. Geoffroy 1838, Ann. Sci. Nat. Zool. (Paris), ser. 2, 10: 126.

Type Species: Mus cahirinus É. Geoffroy 1803

Synonyms: Acanthomys Lesson 1842; Acosminthus Gloger 1841 .

Species and subspecies: 19 species in 3 subgenera:

Subgenus Acomys (Acomys) I. Geoffroy 1838

Subgenus Acomys (Peracomys) F. Petter and Roche 1981

Subgenus Acomys (Subacomys) Denys, Gautun, Tranier, and Volobouev 1994

Species Acomys (Acomys) airensis Thomas and Hinton 1921

Species Acomys (Acomys) cahirinus (E. Geoffroy 1803)

Species Acomys (Acomys) chudeaui Kollman 1911

Species Acomys (Acomys) cilicicus Spitzenberger 1978

Species Acomys (Acomys) cineraceus Heuglin 1877

Species Acomys (Acomys) dimidiatus (Cretzschmar 1826)

Species Acomys (Acomys) ignitus Dollman 1910

Species Acomys (Acomys) johannis Thomas 1912

Species Acomys (Acomys) kempi Dollman 1911

Species Acomys (Peracomys) louisae Thomas 1896

Species Acomys (Acomys) minous Bate 1905

Species Acomys (Acomys) mullah Thomas 1904

Species Acomys (Acomys) nesiotes Bate 1903

Species Acomys (Acomys) percivali Dollman 1911

Species Acomys (Acomys) russatus Wagner 1840

Species Acomys (Acomys) seurati Heim de Balsac 1936

Species Acomys (Acomys) spinosissimus Peters 1852

Species Acomys (Subacomys) subspinosus (Waterhouse 1837)

Species Acomys (Acomys) wilsoni Thomas 1892

Discussion: A brief list of species and subspecies made by Setzer (1975); the arrangement of species provided by Musser and Carleton (1993) based on review of literature and study of specimens; chromosomal reviews by Matthey (1965 a, b, 1968), Volobouev et al. (1991), Sokolov et al. (1992, 1993), and Denys et al. (1994) and regional chromosomal studies of species (cited in the species accounts); study of molar occlusal patterns (Denys et al., 1994; F. Petter, 1983), and spermatozoal morphology (Baskevich and Lavrenchenko, 1995; Breed, 1995 a); biochemical and molecular analyses of large species-clusters (Barome et al., 1998, 2000; Janecek et al., 1991) and smaller assemblages cited in the species accounts; regional systematic revisions (referenced in the species accounts); and review of geographic distributions (Bates, 1994) have all contributed to the present understanding of species-limits within Acomys, their geographic ranges, and phylogenetic relationships. Regrettably, there is still no comprehensive taxonomic revision of the genus incorporating morphological as well as chromosomal and molecular data. Extant species are sorted into three subgenera ( Acomys, Peracomys, and Subacomys), but these groupings require reassessment by systematic revision. Van der Straeten (1994) provided a bibliography of Acomys from Africa and the Middle East that is coded by species and subjects. Our allocation of species to subgenera follows Denys et al. (1994).

According to Denys (1990 b), the earliest fossil representatives of Acomys were found in Southern African sediments at least 4.5 million years old (early Pliocene; see also Avery, 1998, 2000, and Senut et al., 1992). Its evolutionary history undoubtedly extends back in time even farther because Geraads (2001) described Preacomys, considered a "forerunner" of Acomys, based upon isolated molars from late Miocene sediments in Ethiopia (Chorora). Barome et al. (2001) presented two biogeographic hypotheses for the center of species’ origin and their dispersion. One recognizes origin of Acomys in southern Africa and dispersal northwards along with subsequent evolution into species. The other suggests that East Africa (Ethiopia and Kenya) is the center, with dispersion and attendant speciation in one direction to the Mediterranean region, and in another to southern Africa. In either scenario, "The speciation process could also have been caused by a progressive fragmentation of the distribution area, resulting from the formation of the Rift Valley in its south-western part, or from the extension of tropical forest zones dividing the savannah domain into mosaic blocks during climatic fluctuations and isolating the different species by vicariance" (Barome et al., 2001).