A new species of Liolaemus (Reptilia: Squamata) of the Liolaemus capillitas clade (Squamata, Liolaemini, Liolaemus elongatus-kriegi group) from Sierra de Velasco, La Rioja Province, Argentina.

A new species of the Liolaemus capillitas clade is described. Liolaemus galactostictos sp. nov. differs from other members of its group by a combination of morphological and molecular traits, in particular its black dorsal coloration pattern not found in any other Liolaemus species. Liolaemus galactostictos sp. nov. is only known from its type locality. This new species is found in rocky fields surrounded by grasslands on the top of the Velasco Mountains, a ¨sky island environment¨, in northwestern Argentina. As well as other members of its clade this species seems to be strictly saxicolous, viviparous and feeds on insects.

Liolaemus duellmani Cei, 1978 (Reptilia: Squamata: Liolaemini), redescription of the holotype and variation in a microendemic and inadequately known species of Liolaemus from Northwestern Patagonia.

Liolaemus duellmani is a microendemic lizard described from southern Mendoza, Argentina, representing the southernmost distribution of the Liolaemus montanus species group. The original description was based on a small batch of preserved material and a juvenile collected alive. Along the years, this poorly known species was rarely collected or observed in the field, with no additional reports or findings published until a recent description of an adult female which was considered as a rediscovery of the species. Here, we redescribe the species and describe variation on external morphology, coloration, and some natural history observations.