A new lizard of the Liolaemus walkeri clade (Squamata: Liolaemidae) endemic to northern Chile

Abstract

The Liolaemus walkeri clade comprises small, slender lizards, most species of which exhibit ventral melanism and a fragmented dark vertebral line. These lizards inhabit high Andean zones of Peru, although two field guide include photographs of L. tacnae from northern Chile, without voucher specimens or published scientific studies to support this taxonomic assignment. We recently examined specimens labeled L. cf. tacnae from Quebrada Blanca, Tarapacá Region, Chile, and performed morphological analyses, providing the first taxonomic assessment of a population of the L. walkeri clade outside Peru. Males of this population exhibit melanism on the throat and belly, and both sexes lack precloacal pores, among other diagnostic traits. We propose that this population represents a new species and highlight morphological characters of the L. walkeri clade that do not match those of the subgenus Liolaemus (sensu stricto). The L. walkeri clade lacks two of the three external characters used to diagnose the subgenus and does not exhibit some of the defining characters of the L. alticolor-bibronii group, where this clade is currently been placed by some studies. This observations suggest the need to evaluate the existence of a third subgenus of Liolaemus in future research.