The Amazonian lizard Anolis trachyderma was studied at three sites stretching from eastern Ecuador to the central Amazon of Brazil. These lizards occupy low vegetation and leaf litter microhabitats in well-shaded, damp rain forest. Their body temperatures are low (27.8 C on average) and only slightly higher than corresponding substrate and air. They are as likely to be active on cloudy as on sunny days but are usually found in shade. The diet is varied, but dominated volumetrically by grasshoppers-crickets, insect larvae-eggs-pupae, spiders, roaches, and lizard shed skin. Although dietary overlaps among populations are low, no significant differences in prey choice existed based on a randomization analysis. Locality-based and sexual variation in morphology was evident. Overall, A. trachyderma appears similar ecologically across a large portion of the Amazon. Comparisons with three ecologically similar anoles, Anolis nitens scypheus (sympatric with A. trachyderma) and Anolis humilis (no range overlap), reveal similar microhabitat use, body temperatures, and diets, but substantially different morphology. The ecomorph concept may not apply as well to mainland anoles as to island ones, possibly because taxonomically distant lizard species may have had a stronger historical effect on mainland anoles than on island species.