Uncovering New Diversity Among Blue-Scaled Desert Lizards: A New Species of Liolaemus from Southern Peru and Remarks on the Taxonomy of Liolaemus poconchilensis

We describe a new species of lizard of the genus Liolaemus from southern Peru, previously assigned to or confused with L. poconchilensis. The new species belongs to the L. reichei clade of the L. montanus group and is characterized by a “phrynosaurian” morphotype, sexual dimorphism, and the presence of conspicuous blue scales on the flanks. It differs from L. poconchilensis and other geographically and phylogenetically related species by a unique combination of morphometric and meristic characters, including snout–vent length, tail length, number of temporal scales, number of infralabials, and number of scales around the midbody. Furthermore, molecular phylogenetic analyses support its recognition as an independent evolutionary lineage, recovered in a clade separate from L. poconchilensis. Genetic divergence between L. poconchilensis and the new species ranges from 10.24% to 12.47%, with a mean of 11.28%. The new species inhabits the hyperarid Pacific desert of southern Peru, between 699 and 939 m a.s.l., in an area with sparse vegetation and strong environmental aridity. Its apparently restricted distribution, together with observed habitat loss and increasing anthropogenic disturbance, suggests that this species may be highly threatened. Therefore, we preliminarily recommend its classification as Critically Endangered under IUCN criteria.