Sistemática, ecologia e zoogeografia dos Tropidurus do grupo Torquatus ao sul do Rio Amazonas (Sauria, Iguanidae)

Abstract

This paper is a systematic revision of the lizards of the genus Tropidurus (torquatus group) occurring south of the Rio Amazonas. Following an analysis of meristic characters in five areas where lizards with different types of mite pockets occur synpatrically, eleven species are recognized, seven of which described as new. Diagnoses, descriptions and geographic distribution are given for each species, and an artificial key to species is presented. Ecologically, there seem to be two species assemblages: the first includes all species with wide geographic distribution, and the second includes species with restricted distributions, usually limited to mountain or sandy soil areas. Probably present climatic conditions are more suitable for the first group, than for the second. A model based on the geographic ecology of the recent past of a pair of species is proposed to explain the present complex distribution of some species of the torquatus group. The geographic differentiation of T. torquatus and T. hygomi is studied and a sequence of events proposed to explain its origin, ecologic differentiation and evolution.