Journal of Undergraduate Research


anatomy, forelimb, new drepanosaur, behavior models, extinct species


Physical and Mathematical Sciences


Geological Sciences


Introduction: I recently discovered a new genus of reptile from the Triassic period (roughly 225 million years ago). Reptiles like it are called “drepanosaurs,” and share many unique features such as large claws, unusual, humped shoulder blades, opposable fingers, and prehensile tails. Many of these structures appear to be well-suited for climbing, and the scientific community generally considers drepanosaurs to be arboreal. My new specimen, however, is more complete than previous discoveries have been, and it includes skeletal features that could indicate a digging lifestyle. Digging and climbing are on opposite ends of the behavioral spectrum, so my study seeks to determine which lifestyle is the best match for my animal. In order to do this, I used both subjective and objective approaches. Subjectively, I compared the anatomy of my new drepanosaur to the anatomy of modern animals to which have been used as metaphors for drepanosaur movement. Objectively, I collected skeletal measurements from modern digging and climbing animal populations in order to statistically determine whether my drepanosaur has the adaptations that predict digging and climbing. My study was restricted to the features of the drepanosaur forelimb, leaving other skeletal regions as potential candidates for future research.