"Conodonts are extinct primitive vertebrates that attract widespread interest because of the insight they provide into the earliest vertebrate skeleton which they manifest as the mineralized ‘elements’. These teeth dominate a fossil record that is among the richest and most complete. To date, this record has been exploited successfully but solely for its biostratigraphic significance; the evolutionary significance of lineages, reconstructed through biostratigraphy, has not been realised because the tooth function of conodont elements has been determined only very recently.It is my aim to draw together these two strands of research, using state of the art methods of synchrotron radiation x-ray tomographic microscopy to uncover the ontogeny of occlusal elements and derive digital models using computed tomography that will be subject to virtual occlusal modelling to inform loads in FE Analyses of element function. Predictions from FEA will be tested using microwear and mesowear analyses characterised using optical profilometry, and through EBSD analysis of element microstructure.This seminal study will revolutionise both our understanding of the conodont fossil record – the role of intrinsic innovation versus extrinsic forces of competition and environmental change, it will also establish an entirely new suite of investigative tools to the discipline. The study will also demonstrate the importance of biostratigraphic and taxonomic data and how it is possible to integrate traditional and state of the art approaches in a world-class research programme.BROADER IMPACT: Evolutionary developmental biologists interested in the primitive vertebrate skeleton and isotope geochemists interested in the use of conodont apatite as a proxy for seawater chemistry in deep time, together facilitating a new vista of research integrating evolutionary patterns, feeding ecology and environmental variations revealed in seawater chemistry."