A multivariate analysis of the fringe-toed lizards of the Acanthodactylus scutellatus group (Squamata: Lacertidae): systematic and biogeographical implications

The taxonomy of the fringe-toed lizards of the Acanthodactylus scutellatus group has long been unstable and no consensus exists on the systematic status of its various forms. A multivariate analysis of morphological characters, performed on over 1000 specimens from most of the African range of this group, allowed us to clarify the specific allocation of most of the Saharan populations included in this species group. Based on comparisons of morphology between allopatric and sympatric populations of this complex, we propose the recognition of six biological species. Our results confirm the specific status of Acanthodactylus aureus, A. dumerili, A. scutellatus, A. longipes and the recently described A. taghitensis. In addition, we re-validate A. senegalensis (occurring from Mauritania and Mali south to Senegal), which has been treated as a synonym of A. dumerili by previous authors. Acanthodactylus longipes is reported for the first time from coastal Mauritania, and A. taghitensis (previously known only from a very small region in Algeria) is reported from continental Mauritania. The systematic section of this paper includes a full list of examined material, diagnosis and known distribution of each species, in addition to some information on geographical variation and ecology. A key for specific identification is provided as an appendix.