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HOME --> CLASS MAMMALIA
--> ORDER RODENTIA
--> SUBORDER MYOMORPHA
--> SUPERFAMILY Muroidea
--> FAMILY Muridae
--> SUBFAMILY Gerbillinae
GENUS Taterillus
| Author: | Thomas, 1910. | | Citation: | Ann. Mag. Nat. Hist., ser. 8, 6: 222. | | Type Species: | Gerbillus emini Thomas, 1892. | | Comments: | Tribe Taterillini, Subtribe Taterillina. Robbins (1971) proposed a new dental terminology for the genus based on a large sample of T. gracilis, analysed (1973) nongeographic variation drawn from the same sample, and summarized (1977) morphometric and chomosomal differentiation among the seven species that he considered valid (only T. petteri and T. tranieri have since been added). Chromosomal data were reported for some species by Matthey and F. Petter (1970) and karyotypic information was summarized by Qumsiyeh and Schlitter (1991). Like many genera of African muroid rodents, Taterillus requires critical systematic revision to determine species definitions and their distributional limits. Several of the species now recognized are morphologically closely similar to one another, prompting many workers to consider them "sibling" or cryptic species (Dobigny et al., 2002a, 2003; Sicard et al., 1988). Recently, Volobouev and Granjon (1996:47) documented a sex-chromosome system in West African T. arenarius, summarized all chromosome data for the species of Taterillus (and provided references), and noted that "These data clearly show that karyotype evolution in Taterillus is still continuing. Taking into account the apparently frequent occurrence of tandem translocations and pericentric inversions in the evolution of Taterillus and the important role of these rearrangements in the establishment of reproductive isolation . . ., the existence of other chromosomal races and species is extremely likely." This prediction was recently realized by discovery of two new cytotypes ("new cryptic species"), each reproductively isolated from one another, in samples from the Lake Chad area in W Chad and SE Niger (Dobigny et al., 2002a), and a new species (T. tranieri) from Mali and Mauritania diagnosed primarily by karyotype (Dobigny et al., 2003). Apparently the species of Taterillus in West Africa (T. arenarius, T. gracilis, T. petteri, T. pygargus, and T. tranieri) comprise a monophyletic complex of sibling species defined by the same autosome-gonosome translocation, which has not been seen in species from Central and East Africa (Dobigny et al., 2003; Volobouev and Granjon, 1996). Dobigny et al. (2003:300) use "karyospecies" to describe these "cryptic" species "that can only be unambiguously characterized as good biological species by means of their karyotype." Evolutionary history as documented by fossils extends back to late Pliocene of subsaharan Africa (Denys, 1987a, 1989b, 1999; see review by Wessels, 1998). |
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