Taterillus petteri Gautun, Tranier, and Sicard, 1985 . Mammalia, 49:538.

TYPE LOCALITY: Burkina Faso (Upper Volta), Oudalan Prov., near Oursi Pond; 14°38'N, 00°26'W (as refined by Sicard et al., 1988:188) .

DISTRIBUTION: Sahel savannah of E Burkina Faso and W Niger west of Niger River .

COMMENTS: As explained by Ansell (1989a), the availability of petteri should properly date from its first checklist citation (Gautun et al., 1985), not from its later formal description (Sicard et al., 1988). According to Sicard et al. (1988), T. petteri is confined to the loop of the Niger River and is parapatric with T. gracilis, from which it differs in morphology, ecology, biochemistry, and physiology. In the same paper, they stated that petteri may actually be conspecific with angelus (from Gambia), although they acknowledged not examining the holotype of the latter, and they speculated that angelus and lacustris may prove to be the same, but, because the type of the former is young and that of the latter is old, the relationship is difficult to demonstrate. The contribution of petteri to the systematic literature of African gerbils hardly improves the picture of relationships among populations of Taterillus .