Dr. D'Emic is a vertebrate paleontologist interested in the evolution of dinosaurs, the inference of paleobiology and paleoecology in extinct animals from fossil microstructure, and the Cretaceous faunal dynamics of North America. His research program focuses on sauropod dinosaurs, which are interesting to the public and scientists alike due to their extreme body size. No terrestrial animal before or since rivaled their mass, so sauropods can be thought of as end members in terms of the physiological, biomechanical, and ecological conditions surrounding the evolution of extreme body size. Sauropods were common and diverse throughout most of the Mesozoic Era for about 150 million years their 170+ known species formed the predominant herbivore component of many terrestrial ecosystems. This ubiquity makes sauropods an excellent group for investigating evolutionary, ecological, and biogeographic patterns over long timescales. Dr. D'Emic's research integrates fieldwork, bone histology, taxonomic work, and phylogenetic analysis to understand the biological and geological factors involved in the origin and extinction of sauropods, and how these factors combined to allow them to surpass all other terrestrial animals in body size.
Other current areas of research include the systematics, paleobiology,and paleoecology of mosasaurs (Cretaceous marine reptiles), the evolution of growth rates in theropod (meat-eating) dinosaurs, and the anatomy and microstructure of peculiar, hollow osteoderms ("armor") in some sauropod dinosaurs.