Lizards of the genus Tropidurus (Iguania : Tropiduridae) from the Serraniade Huanchaca, Bolivia: New species, natural history, and a key to the genus

Four species of Tropidurus live in the vicinity of the Serrania de Huanchac a, an isolated mountain range overlapping the northeastern border of Bolivi a and Brazil. We describe three of the four species as new to science. A ne w saxicolous species is most similar to T. melanopleurus. Like T melanopleu rus, females of the new species are smaller and more brightly colored than males. A new arboreal species resembles T. spinulosus and differs most stri kingly by its squamation and brighter coloration. A second new saxicolous s pecies resembles T. etheridgei and appears to develop gravid coloration, a phenomenon widespread among iguanians but previously unreported for species of Tropidurus. Tropidurus umbra ochrocollaris from the Serrania de Huancha ca is ecologically and morphologically similar to T u. ochrocollaris elsewh ere in Amazonia, but it has a short dorsal crest like the nominate race. Tr opidurus spinulosus guarani Alvarez, Cei, and Scolaro is accorded specific status.