Comparative inner ear anatomy of side-necked turtles based on microcomputed tomography and its systematic and functional implications

Abstract

Microcomputed tomography (microCT) is a cutting-edge technology that allows nondestructive imaging of internal anatomical structures that are poorly known for fossilsand living organisms. These techniques have been used to study details of skull anatomy,including braincase osteology, carotid circulation, and vestibular system (inner ear). The morphology of such structures is related to both ecology and phylogeny (evolutionary relationships), but is poorly understood in turtles. The vestibular system is responsible forthe balance and accurate movement coordination of the organisms. Its morphology has been suggested to be related to the locomotion mode, hence to the environment in which animals live. The goal of this project is to amplify and improve the candidate's skills in applying ¼CT scanning to virtually reconstruct several fossil turtle taxa at Dr. Roger Benson laboratory at the University of Oxford, UK. The proposed work will strengthenthe student's knowledge both on the employed methodology and also on the inner anatomy and evolution of podocnemidoids, a group of extant South hemisphere sidenecked turtles. Scans already available in Dr Benson's lab will provide a large starting sample of ¼CT data for extant pleurodires. The candidate will work along with the supervisor and laboratory associates scanning specimens and reconstructing them on Mimics, an industry standard software for 3D modelling of fossils and living organisms. This will be important both to acquire knowledge on the use of modern methods and for setting oversea partnerships, which will surely help the candidate's undergraduate career. (AU)