Prehistoric eel-like vertebrate had world’s sharpest teeth

Nature : Conodonts, extinct jawless marine vertebrates that lived from the Precambrian to some time in the Triassic, were the first animals to evolve teeth—and they had the sharpest teeth ever known. In a study published in the Proceedings of the Royal Society B, Philip Donoghue of the University of Bristol in the UK created computer models of eight pairs of conodont teeth and used finite-element analysis, a technique to model the effects of physical forces on airplanes, to compare the teeth with bat molars of similar size. Although conodont teeth were very delicate, with tips 2 micrometers across, their sharpness combined with a 90 degree slicing and interlocking motion concentrated the physical force they could apply. Sharper teeth are more likely to break, but there’s also some evidence that conodonts, unlike modern vertebrates, could resharpen worn and damaged teeth throughout their lives.