Professor Mark Andrew Purnell is a British palaeontologist, Professor of Palaeobiology at the University of Leicester. Purnell is an expert in conodont biostratigraphy (principally Carboniferous) and conodont palaeobiology, focussing especially on attempts to uncover the function of conodont elements. Using conventional functional morphology, physical modelling and microwear analysis, Purnell uncovered unequivocal evidence that conodont elements had performed a mechanical tooth function in life, resolving a palaeobiological debate that had run for more than a century. His work has expanded in recent years to analysing feeding mechanisms of extinct vertebrates more generally, exploiting microwear, including validation studies based on extant stickleback fish.