Meeting Abstract
Various selective pressures have undoubtedly influenced the adaptive radiation of defense mechanisms across taxa. While the correlates that favor the evolution of morphological defenses such as noxious sprays, spines, quills, and dermal armor are well studied, we know far less about the factors that contribute to variation in these defenses within a single taxon. Dermal armor is energetically costly and, in the case of cingulates, the multiple selective pressures that drive the maintenance and diversity of their heavily armored carapaces are largely unknown. In this study, we use CT scans and Amira imaging software to quantify and compare the relative thickness, surface area, and volume of armor from 13 armadillo species. Using these data, we plan to further investigate the potential correlates of dermal armor such as climate, habitat type and usage, intraspecies interactions, and predation using phylogenetic generalizes least squares analyses. Early results show dermal armor of armadillos appears to vary in these measures among species. Ongoing work indicates species that are larger in size and more exposed to predation have more armored carapaces. We hope to disentangle the selective pressures that play a role in the evolution of armadillo carapaces and build a theoretical framework by which to help predict the adaptive radiation of body armor in extinct and extant mammals.
