The fossil record of freshwater crayfish is surprisingly sparse, comprising mostly trace fossils, some body fossils and rarely gastroliths. Paleontologists from Flinders University, the University of New South Wales, Canterbury Museum and the University of Canterbury have now discovered that a tiny molar on mandibles (jaws) of Gondwanan freshwater crayfish has a hard robust apatite layer that may well facilitate fossilization. They’ve found eight...