Liolaemus heliodermis, a new lizard from northwestern Argentina with remarks on the content of the Elongatus group (Iguania : Tropiduridae)

We provide a diagnosis for the Liolaemus elongatus group which currently in cludes six species (including the species described herein) of midsized, lo ng-tailed, primarily saxicolous lizards. Most of these species are distribu ted along the Andean Cordillera of western Argentina where they principally occur at elevations above 1000 m. Here we describe Liolaemus heliodermis, a new species belonging to this group from the region where the Cumbres Cal chaquies and the Sierra del Aconquija mountain ranges converge in northwest ern Tucuman Province. The new species differs from all other members of the elongatus group in several meristic characters and in the distinct colorat ion of the males: black heads with vibrant yellow torsos. Liolaemus heliode rmis is the most northerly distributed member of the elongatus group and is the only member of the group known to occur in Tucuman Province. Prelimina ry data on the biology of L. heliodermis and the relationships of the new s pecies to other members of the elongatus group are discussed.