Ken S. Toyama
Breviora 554 (1), 1-20, (26 May 2017) https://doi.org/10.3099/0006-9698-554.1.1
KEYWORDS: Adaptive radiation, diversity, ecomorphology, evolutionary history, Stenocercus, Tropidurus
Habitat use can be used to predict morphological proportions among lizard species, building links between form and function. Among the Tropidurinae, a species-rich clade of lizards, these ecomorphological relations have not been studied for all the genera, and previous work still leaves some important gaps within this topic. In this study, a large-scale ecomorphological assessment of 10 genera found within this clade was performed with respect to habitat use categories. The results of a multivariate analysis that considered 14 morphological traits showed that Stenocercus was the most morphologically diverse genus within this clade. Tropidurus was the genus that showed a greater diversity of specialized species regarding habitat use, showing representative species for each category and the respective specialized morphologies; however, this apparent diversity was limited in general terms and appeared to be restrained by evolutionary history. Further analyses in a phylogenetic context showed that the effect of habitat use was not strong enough to explain the morphological diversity of the Tropidurinae. Finally, a phylogenetic signal test showed that all individual traits were dependent on evolutionary history; additionally, the limb traits exhibited a stronger phylogenetic influence than the rest of the traits. The Tropidurinae were found to be a morphologically diverse group of lizards where the influence of habitat use on the morphology seems to be constrained by specific morphological limits imposed by the evolutionary history of each genus. Further studies are needed to assess the effect of habitat use in the morphology within each separate genus of this clade, especially for those for which information is scarce.